Probably fix flaky test TestExecTTY
Probably fix flaky test TestExecTTY

sleep 2 seconds before exec exit to make sure
the output of `cat /foo` will be read

Signed-off-by: Lei Jitang <9ac444d2b5df3db1f31aa1c6462ac8e9e2bde241@huawei.com>

amatsus/docker,Altiscale/docker,splunk/docker,lixiaobing1/docker,bdwill/docker.github.io,sunyuan3/docker,jzwlqx/denverdino.github.io,cyli/docker,sarnautov/moby,13W/docker,johnstep/docker.github.io,icecrime/docker,danyalKhaliq10p/moby,ktraghavendra/docker,swasd/baleno,aduermael/docker.github.io,Tenk42/docker,nigelpoulton/docker,phiroict/docker,joaofnfernandes/docker.github.io,YujiOshima/docker,justyntemme/docker,ffoysal/docker,afein/docker,justincormack/docker,achanda/docker,LuisBosquez/docker.github.io,gschaetz/moby,docker/docker,imeoer/hypercli,rremer/moby,tklauser/docker,HackToday/docker,ColinHebert/docker,mahak/docker,raja-sami-10p/moby,londoncalling/docker.github.io,dsheets/moby,jc-m/docker,fcrisciani/docker,kencochrane/docker,mstanleyjones/docker,arun-gupta/docker,kimh/docker,anweiss/docker.github.io,kunalkushwaha/docker,hyperhq/hypercli,endophage/docker,gigidwan/docker,luxas/docker,twaugh/docker,JeffBellegarde/docker,yp-engineering/docker,catinthesky/docker,tophj-ibm/docker,thaJeztah/docker.github.io,runcom/docker,softprops/docker,YuPengZTE/docker,raja-sami-10p/moby,cnaize/docker,mixja/docker,madhanrm/docker,gjaskiewicz/moby,mauidev/docker,zhuguihua/docker,noxiouz/docker,ItsVeryWindy/docker,gdevillele/docker.github.io,wenchma/docker,shin-/docker.github.io,xiaods/docker,contiv/docker,JimGalasyn/docker.github.io,docker/docker.github.io,Tenk42/docker,TheBigBear/docker,Syntaxide/docker,moul/docker,imkin/moby,laijs/docker,ripcurld0/moby,denverdino/docker.github.io,cr7pt0gr4ph7/docker,swasd/baleno,srust/docker,tmp6154/docker,nawawi/docker,joaofnfernandes/docker.github.io,thaJeztah/docker.github.io,nawawi/docker,LuisBosquez/docker.github.io,ajneu/docker,dgageot/docker,shhsu/docker,flavio/docker,pyotr777/docker,solganik/docker,abhinavdahiya/docker,charleszheng44/moby,ivansaracino/docker,jzwlqx/denverdino.github.io,xiaods/docker,unclejack/docker,maxamillion/docker,Akasurde/docker,Collinux/docker,fangyuan930917/docker,anusha-ragunathan/docker,scotttlin/docker,londoncalling/docker.github.io,YuPengZTE/docker,portworx/docker,ajaymdesai/docker,mathewkoshy493/docker,djs55/docker,jc-m/docker,tpounds/docker,sallyom/docker,icecrime/docker,Shopify/docker,trebonian/docker,TrumanLing/docker,gao-feng/docker,shubheksha/docker.github.io,pyotr777/docker,ktraghavendra/docker,tagomoris/docker,mohmost12/docker,shishir-a412ed/docker,dmcgowan/docker,contiv/docker,kunalkushwaha/docker,LaynePeng/docker,Akasurde/docker,tkopczynski/docker,upmio/docker,gao-feng/docker,maxamillion/docker,mauidev/docker,inatatsu/docker,shin-/docker.github.io,kerneltime/docker,KarthikNayak/docker,sfsmithcha/docker,LuisBosquez/docker.github.io,bearstech/moby,yosifkit/docker,joaofnfernandes/docker.github.io,sanjeo/docker,eskaaren/docker,yongtang/docker,jwhonce/docker,mikebrow/docker,JMesser81/docker,icaoweiwei/docker,upmio/docker,pramodhkp/moby,nguyentm83/docker,Test-Betta-Inc/psychic-barnacle,wenchma/docker,thtanaka/docker,menglingwei/denverdino.github.io,luxas/docker,13W/docker,TheBigBear/docker,brahmaroutu/docker,jloehel/docker,icaoweiwei/docker,nalind/docker,alfred-landrum/docker,stainboy/docker,londoncalling/docker.github.io,ItsVeryWindy/docker,paralin/docker,cloudflare/docker,imkin/moby,mariusGundersen/docker,sfsmithcha/docker,erikh/docker,madhanrm/docker,Shopify/docker,docker-zh/docker.github.io,rhatdan/docker,thaJeztah/docker.github.io,shin-/docker.github.io,kyle-wang/docker,yosifkit/docker,HideoYamauchi/docker,rancher/docker,Ramzec/docker,kencochrane/docker,mixja/docker,scollier/docker,errordeveloper/docker,mixja/docker,fangyuan930917/docker,jecarey/docker,fangyuan930917/docker,Microsoft/docker,tophj-ibm/moby,portworx/docker,danix800/docker.github.io,eskaaren/docker,sheimi/docker,rhardih/docker,toli/docker,sean-jc/docker,bonczj/moby-json-file-logger,duglin/docker,Distrotech/docker,jimjag/docker,jzwlqx/denverdino.github.io,rickyzhang82/docker,bluebreezecf/docker,14rcole/docker,Altiscale/docker,POLJM242/docker,supasate/docker,shubheksha/docker.github.io,dmcgowan/docker,endocode/docker,tophj-ibm/moby,ibuildthecloud/docker,fcrisciani/docker,Aegeaner/docker,endophage/docker,Test-Betta-Inc/psychic-barnacle,imkin/moby,cr7pt0gr4ph7/docker,haveatry/docker,rhatdan/storage,OnePaaS/docker,bluebreezecf/docker,jameszhan/docker,danyalKhaliq10p/moby,mikedougherty/docker,Altiscale/docker,estesp/docker,dperny/docker,medallia/docker,johnstep/moby-moby,justincormack/docker,trebonian/docker,rancher/docker,KarthikNayak/docker,ncdc/docker,rhatdan/docker,mohmost12/docker,Mashimiao/docker,Aegeaner/docker,containers/storage,moby/moby,charleswhchan/docker,joaofnfernandes/docker.github.io,Syntaxide/docker,jhorwit2/docker,dgageot/docker,unclejack/docker,qudongfang/docker,docker/docker,yongtang/docker,DoraALin/docker,mkumatag/docker,konstruktoid/docker-1,stainboy/docker,tonistiigi/docker,achanda/docker,sdurrheimer/docker,x1022as/docker,ffoysal/docker,rkazak/docker,alexisbellido/docker.github.io,rillig/docker.github.io,bfirsh/docker,shin-/docker.github.io,mikebrow/docker,sterchelen/docker,ZJUshuaizhou/docker,michelvocks/docker,danix800/docker.github.io,davinashreddy/docker,inatatsu/docker,LaynePeng/docker,cmehay/docker-1,shubheksha/docker.github.io,hypriot/docker,qudongfang/docker,nalind/docker,harche/docker,anortef/docker,TheBigBear/docker,justincormack/docker,docker/docker.github.io,madhanrm/docker,ivansaracino/docker,phiroict/docker,dbonev/docker,dims/docker,mgoelzer/docker,mssola/docker,willmtemple/docker,mbanikazemi/docker,justyntemme/docker,Test-Betta-Inc/psychic-barnacle,AkihiroSuda/docker,arun-gupta/docker,dperny/docker,sanscontext/docker.github.io,sarnautov/moby,supasate/docker,Ramzec/docker,ckeyer/docker,BenHall/docker,containers/storage,justyntemme/docker,KingEmet/docker,noxiouz/docker,moypray/docker,michelvocks/docker,kyle-wang/docker,rremer/moby,tmp6154/docker,geekylucas/docker,twaugh/docker,cmehay/docker-1,denverdino/docker.github.io,zhangjianfnst/docker,isubuz/docker,cpuguy83/docker,YujiOshima/docker,denverdino/docker.github.io,gdevillele/docker.github.io,JeffBellegarde/docker,mikedanese/docker,endocode/docker,danix800/docker.github.io,jvanz/docker,moby/moby,csfrancis/docker,umerazad/docker,bearstech/moby,moul/docker,mikedanese/docker,SaiedKazemi/docker,noironetworks/docker,laijs/docker,lixiaobing1/docker,nawawi/docker,hallyn/docker,mgoelzer/docker,twaugh/docker,dccurtis/docker,aditirajagopal/docker,johnstep/docker.github.io,gigidwan/docker,ItsVeryWindy/docker,ColinHebert/docker,JMesser81/docker,qudongfang/docker,shhsu/docker,denverdino/denverdino.github.io,tianon/docker,flavio/docker,sfsmithcha/docker,naveed-jamil-tenpearls/moby,nalind/docker,prertik/docker,fsoppelsa/docker,containers/storage,laijs/docker,BSWANG/denverdino.github.io,sanjeo/docker,erikstmartin/docker,ailispaw/docker,Mokolea/docker,docker/docker.github.io,shhsu/docker,whuwxl/docker,jlhawn/docker,bdwill/docker.github.io,dbonev/docker,gschaetz/moby,clintonskitson/docker,prertik/docker,gnailuy/docker,darrenstahlmsft/docker,alfred-landrum/docker,dnephin/docker,crosbymichael/docker,Neverous/docker,willmtemple/docker,mstanleyjones/docker,kolyshkin/docker,sheimi/docker,JimGalasyn/docker.github.io,xuxinkun/docker,asbjornenge/docker,tonistiigi/docker,phiroict/docker,hqhq/moby,nawawi/docker,dsheets/moby,menglingwei/denverdino.github.io,nghiant2710/docker,londoncalling/docker.github.io,ktraghavendra/docker,mtesselH/docker,aduermael/docker.github.io,BSWANG/denverdino.github.io,KingEmet/docker,SaiedKazemi/docker,zhuguihua/docker,hyperhq/hypercli,umerazad/docker,softprops/docker,pradipd/moby,jlhawn/docker,bonczj/moby-json-file-logger,jwhonce/docker,erikh/docker,sallyom/docker,konstruktoid/docker-upstream,johnstep/docker.github.io,docker-zh/docker.github.io,konstruktoid/docker-upstream,sanscontext/docker.github.io,yp-engineering/docker,kerneltime/docker,anweiss/docker.github.io,POLJM242/docker,alexisbellido/docker.github.io,sanscontext/docker.github.io,angryxlt/docker,laijs/moby,mtrmac/docker,joeuo/docker.github.io,Morsicus/docker,BSWANG/denverdino.github.io,mathewkoshy493/docker,hallyn/docker,sanscontext/docker.github.io,Microsoft/docker,moby/moby,cr7pt0gr4ph7/docker,stevvooe/docker,kolyshkin/moby,srust/docker,dccurtis/docker,pradipd/moby,crosbymichael/docker,TrumanLing/docker,kolyshkin/docker,cmehay/docker-1,medallia/docker,toli/docker,scotttlin/docker,denverdino/denverdino.github.io,charleszheng44/moby,anweiss/docker.github.io,resin-io/docker,sunyuan3/docker,ColinHebert/docker,jzwlqx/denverdino.github.io,brahmaroutu/docker,allencloud/docker,JimGalasyn/docker.github.io,SvenDowideit/docker,konstruktoid/docker-upstream,mahak/docker,xiekeyang/docker,ailispaw/docker,aaronlehmann/docker,ZJUshuaizhou/docker,hustcat/docker,jameszhan/docker,icaoweiwei/docker,estesp/docker,joeuo/docker.github.io,mssola/docker,bfirsh/docker,mbanikazemi/docker,Jimmy-Xu/hypercli,jasonamyers/docker,alexisbellido/docker.github.io,pragyasardana/Docker-cr-combined,thaJeztah/docker,dccurtis/docker,zhangjianfnst/docker,ckeyer/docker,denverdino/denverdino.github.io,fcrisciani/docker,imeoer/hypercli,mtanlee/docker,nguyentm83/docker,bluebreezecf/docker,pecameron/docker,PatrickLang/moby,cloudflare/docker,projectatomic/docker,anujbahuguna/docker,rhatdan/storage,alexisbellido/docker.github.io,jthelin/docker,johnstep/moby-moby,afein/docker,docker/docker,lixiaobing1/docker,vincentwoo/docker,14rcole/docker,alexisbellido/docker.github.io,tkopczynski/docker,arun-gupta/docker,ZJUshuaizhou/docker,x1022as/docker,tkopczynski/docker,swasd/baleno,aidanhs/docker,crosbymichael/docker,naveed-jamil-tenpearls/moby,carolfh/docker,anweiss/docker.github.io,fsoppelsa/docker,softprops/docker,xuxinkun/docker,dnephin/docker,estesp/docker,medallia/docker,HuKeping/docker,jwhonce/docker,shubheksha/docker.github.io,Morsicus/docker,srust/docker,cyli/docker,Mashimiao/docker,kencochrane/docker,gdevillele/docker.github.io,HideoYamauchi/docker,runcom/docker,resin-io/docker,coreos/docker,geekylucas/docker,errordeveloper/docker,kolyshkin/moby,mtanlee/docker,darrenstahlmsft/docker,splunk/docker,djs55/docker,skatsuta/docker,nghiant2710/docker,Ramzec/docker,moxiegirl/docker,noxiouz/docker,xiekeyang/docker,alfred-landrum/docker,stevvooe/docker,gdevillele/docker.github.io,ripcurld0/moby,mike1729/docker,ivansaracino/docker,bearstech/moby,tklauser/docker,jzwlqx/denverdino.github.io,shishir-a412ed/docker,michael-holzheu/docker,troy0820/docker.github.io,yosifkit/docker,jameszhan/docker,Neverous/docker,johnstep/docker.github.io,naveed-jamil-tenpearls/moby,dsau/docker,shishir-a412ed/docker,denverdino/denverdino.github.io,mikebrow/docker,amatsus/docker,AkihiroSuda/docker,paralin/docker,coolljt0725/docker,ibuildthecloud/docker,trebonian/docker,nigelpoulton/docker,mikedougherty/docker,kimh/docker,sheimi/docker,troy0820/docker.github.io,achanda/docker,stainboy/docker,SvenDowideit/docker,mike1729/docker,konstruktoid/docker-upstream,hyperhq/hypercli,ndeloof/docker,gjaskiewicz/moby,Collinux/docker,sean-jc/docker,bonczj/moby-json-file-logger,cyphar/docker,sarnautov/moby,tophj-ibm/docker,johnstep/moby-moby,tbonza/docker,sanscontext/docker.github.io,runcom/docker,xuxinkun/docker,Mashimiao/docker,tophj-ibm/docker,isubuz/docker,clintonskitson/docker,liaoqingwei/docker,kolyshkin/moby,yasiramin10p/moby,menglingwei/denverdino.github.io,cyphar/docker,rkazak/docker,thtanaka/docker,BSWANG/denverdino.github.io,prertik/docker,asbjornenge/docker,KarthikNayak/docker,rkazak/docker,anortef/docker,BrianBland/docker,dongjoon-hyun/docker,akira-baruah/docker,mstanleyjones/docker,lixiaobing10051267/docker,mkumatag/docker,skatsuta/docker,gigidwan/docker,harche/docker,clintonskitson/docker,docker-zh/docker.github.io,jlebon/docker,Tenk42/docker,fsoppelsa/docker,jthelin/docker,diogomonica/docker,kyle-wang/docker,stevvooe/docker,mssola/docker,Jimmy-Xu/hypercli,JMesser81/docker,brahmaroutu/docker,angryxlt/docker,michael-holzheu/docker,cyphar/docker,mtrmac/docker,joeuo/docker.github.io,BSWANG/denverdino.github.io,allencloud/docker,icecrime/docker,catinthesky/docker,aduermael/docker.github.io,rhatdan/storage,13W/docker,noironetworks/docker,moby/moby,joaofnfernandes/docker.github.io,flavio/docker,troy0820/docker.github.io,hallyn/docker,jongiddy/docker,charleszheng44/moby,anusha-ragunathan/docker,toli/docker,upmio/docker,kojiromike/docker,TrumanLing/docker,projectatomic/docker,hypriot/docker,yasiramin10p/moby,xiekeyang/docker,jhorwit2/docker,yasiramin10p/moby,liaoqingwei/docker,menglingwei/denverdino.github.io,joeuo/docker.github.io,djs55/docker,isubuz/docker,ncdc/docker,davinashreddy/docker,catinthesky/docker,kerneltime/docker,sterchelen/docker,pramodhkp/moby,aidanhs/docker,OnePaaS/docker,HuKeping/docker,aaronlehmann/docker,moul/docker,anweiss/docker.github.io,paralin/docker,pecameron/docker,coolljt0725/docker,anujbahuguna/docker,tbonza/docker,dgageot/docker,shubheksha/docker.github.io,sean-jc/docker,tianon/docker,jlebon/docker,dperny/docker,dnephin/docker,jongiddy/docker,tagomoris/docker,dmcgowan/docker,mariusGundersen/docker,endocode/docker,troy0820/docker.github.io,sallyom/docker,jongiddy/docker,hqhq/moby,rancher/docker,ndeloof/docker,sdurrheimer/docker,erikstmartin/docker,jimjag/docker,csfrancis/docker,Jimmy-Xu/hypercli,thaJeztah/docker.github.io,ndeloof/docker,solganik/docker,miminar/docker,HideoYamauchi/docker,pyotr777/docker,londoncalling/docker.github.io,LuisBosquez/docker.github.io,jc-m/docker,inatatsu/docker,jimjag/docker,vdemeester/docker,ZJU-SEL/docker,mtrmac/docker,afein/docker,carolfh/docker,hustcat/docker,Mokolea/docker,denverdino/denverdino.github.io,menglingwei/denverdino.github.io,HackToday/docker,skatsuta/docker,mahak/docker,HackToday/docker,aidanhs/docker,cpuguy83/docker,pragyasardana/Docker-cr-combined,yummypeng/docker,mbanikazemi/docker,aditirajagopal/docker,denverdino/docker.github.io,DoraALin/docker,thtanaka/docker,konstruktoid/docker-1,BrianBland/docker,thaJeztah/docker,luxas/docker,tagomoris/docker,izarov/docker,jimjag/docker,geekylucas/docker,projectatomic/docker,umerazad/docker,rhatdan/docker,AkihiroSuda/docker,jvanz/docker,SvenDowideit/docker,danix800/docker.github.io,ajneu/docker,JimGalasyn/docker.github.io,zhuguihua/docker,ajaymdesai/docker,michelvocks/docker,charleswhchan/docker,Collinux/docker,jvanz/docker,mathewkoshy493/docker,jlhawn/docker,scollier/docker,Shopify/docker,AkihiroSuda/docker,dongjoon-hyun/docker,cpswan/docker,phiroict/docker,dsau/docker,paralin/docker,msabansal/docker,diogomonica/docker,johnstep/docker.github.io,kimh/docker,medallia/docker,YujiOshima/docker,Morsicus/docker,maxamillion/docker,ckeyer/docker,whuwxl/docker,amatsus/docker,Mokolea/docker,Microsoft/docker,erikstmartin/docker,gao-feng/docker,q384566678/docker,ajaymdesai/docker,haveatry/docker,haveatry/docker,charleswhchan/docker,willmtemple/docker,13W/docker,kunalkushwaha/docker,gdevillele/docker.github.io,docker/docker.github.io,anortef/docker,cnaize/docker,sdurrheimer/docker,rillig/docker.github.io,docker-zh/docker.github.io,OnePaaS/docker,lixiaobing10051267/docker,nalind/docker,yp-engineering/docker,denverdino/docker.github.io,yummypeng/docker,cpuguy83/docker,supasate/docker,KingEmet/docker,thaJeztah/docker,ZJU-SEL/docker,portworx/docker,hqhq/moby,gnailuy/docker,solganik/docker,mikedougherty/docker,13W/docker,mtanlee/docker,tklauser/docker,JimGalasyn/docker.github.io,tpounds/docker,bearstech/moby,vijaykilari/docker,mgoelzer/docker,dsau/docker,abhinavdahiya/docker,hypriot/docker,anujbahuguna/docker,flavio/docker,abhinavdahiya/docker,bfirsh/docker,rremer/moby,s7v7nislands/docker,BenHall/docker,JeffBellegarde/docker,laijs/moby,vdemeester/docker,Aegeaner/docker,mtesselH/docker,izarov/docker,gnailuy/docker,moxiegirl/docker,xiaods/docker,thaJeztah/docker,konstruktoid/docker-1,BrianBland/docker,yosifkit/docker,harche/docker,gnailuy/docker,PatrickLang/moby,darrenstahlmsft/docker,duglin/docker,tpounds/docker,yongtang/docker,bdwill/docker.github.io,tonistiigi/docker,jlebon/docker,thaJeztah/docker.github.io,carolfh/docker,HuKeping/docker,kojiromike/docker,zhuohual/docker,mahak/docker,moul/docker,rhardih/docker,vincentwoo/docker,vijaykilari/docker,rickyzhang82/docker,shin-/docker.github.io,moxiegirl/docker,jloehel/docker,ncdc/docker,mohmost12/docker,bdwill/docker.github.io,pramodhkp/moby,laijs/moby,dsheets/moby,moypray/docker,noironetworks/docker,michael-holzheu/docker,rillig/docker.github.io,ibuildthecloud/docker,resin-io/docker,izarov/docker,vincentwoo/docker,Syntaxide/docker,joeuo/docker.github.io,coreos/docker,dims/docker,ripcurld0/moby,cnaize/docker,PatrickLang/moby,YuPengZTE/docker,msabansal/docker,moypray/docker,BenHall/docker,gschaetz/moby,yummypeng/docker,jloehel/docker,sterchelen/docker,vijaykilari/docker,ibuildthecloud/docker,raja-sami-10p/moby,Ramzec/docker,miminar/docker,cyli/docker,jecarey/docker,whuwxl/docker,kojiromike/docker,endophage/docker,gjaskiewicz/moby,rillig/docker.github.io,jasonamyers/docker,mike1729/docker,pecameron/docker,trebonian/docker,msabansal/docker,darrenstahlmsft/moby,pragyasardana/Docker-cr-combined,zhuohual/docker,aditirajagopal/docker,ffoysal/docker,bdwill/docker.github.io,nigelpoulton/docker,tophj-ibm/moby,duglin/docker,s7v7nislands/docker,sunyuan3/docker,Mokolea/docker,ibuildthecloud/docker,Akasurde/docker,SaiedKazemi/docker,eskaaren/docker,csfrancis/docker,zhangjianfnst/docker,Distrotech/docker,cpuguy83/docker,coreos/docker,liaoqingwei/docker,mkumatag/docker,aaronlehmann/docker,ajneu/docker,x1022as/docker,docker/docker.github.io,unclejack/docker,allencloud/docker,sanjeo/docker,splunk/docker,akira-baruah/docker,tmp6154/docker,DoraALin/docker,diogomonica/docker,erikh/docker,davinashreddy/docker,dongjoon-hyun/docker,miminar/docker,cpswan/docker,scotttlin/docker,LuisBosquez/docker.github.io,lixiaobing10051267/docker,q384566678/docker,aduermael/docker.github.io,asbjornenge/docker,danyalKhaliq10p/moby,phiroict/docker,q384566678/docker,darrenstahlmsft/moby,imeoer/hypercli,mtesselH/docker,nghiant2710/docker,hustcat/docker,pradipd/moby,LaynePeng/docker,vdemeester/docker,dims/docker,coolljt0725/docker,wenchma/docker,cloudflare/docker,mariusGundersen/docker,jhorwit2/docker,ailispaw/docker,errordeveloper/docker,contiv/docker,docker-zh/docker.github.io,darrenstahlmsft/moby