fix(store/store_bench): don't use rand
fix(store/store_bench): don't use rand

rand just introduces more noise to the results, don't use it.

xiang90/etcd,njucslqq/etcd,sofuture/etcd,yudai/etcd,rnaveiras/etcd,onlyjob/etcd,linuxcer/etcd,Eagle-X/etcd,dterei/etcd,purpleidea/etcd,buaazp/etcd,yifan-gu/etcd,tguangch/etcd,achanda/etcd,justintung/etcd,dalanlan/etcd,hroyrh/etcd,polvi/etcd,dannysauer/etcd,xychu/etcd,lorneli/etcd,mgoelzer/etcd-fork2,nkhare/etcd,li-ang/etcd,sebschrader/etcd,wfxiang08/etcd,mischief/etcd,jeremyeder/etcd,OyTao/etcd_learning,glensc/etcd,dterei/etcd,hpcloud/etcd,betawaffle/etcd,freeloop1114/etcd,qiaochao911/etcd,jonboulle/etcd,Yhgenomics/etcd,heyitsanthony/etcd,mike-lerch/etcd,hongchaodeng/etcd,gtank/etcd,a-robinson/etcd,Ulexus/etcd,rchicoli/etcd,iamqizhao/etcd,Winslett/etcd,svdata/etcd,cognusion/etcd,fgbreel/etcd,yifan-gu/etcd,mickep76/etcd,fasaxc/etcd,shakefu/etcd,njucslqq/etcd,yyljlyy/etcd,olark/etcd,HideoYamauchi/etcd,youxidev/etcd,joshix/etcd,lumjjb/etcd,shawnps/etcd,arthurcolle/etcd,sebrandon1/etcd,njharman/etcd,tempbottle/etcd,lzbgt/etcd,dannysauer/etcd,coreos/etcd,etcd-io/etcd,plasticbox/etcd,joshix/etcd,freeloop1114/etcd,ajityagaty/etcd,tangkun75/etcd,endocode/etcd,qqsun8819/etcd,onlyjob/etcd,justintung/etcd,honeyqa/etcd,ktateish/etcd,arthurcolle/etcd,ecnahc515/etcd,mike-lerch/etcd,ajityagaty/etcd,tangkun75/etcd,jmptrader/etcd,rnaveiras/etcd,xueshanf/etcd,kingland/etcd,shakefu/etcd,sofuture/etcd,raoofm/etcd,heyitsanthony/etcd,mitake/etcd,steveeJ/etcd,Timer/etcd,jefby/etcd,chai2010-playground/etcd,cockroachdb/etcd,openedbox/etcd,barakmich/etcd,gae123/etcd,buaazp/etcd,CrazyJvm/etcd,swingbach/etcd,tamird/etcd,spacejam/etcd,SivagnanamCiena/etcd,gtank/etcd,CrazyJvm/etcd,spotify/etcd,siddontang/etcd,insequent/etcd,junxu/etcd,hzy001/etcd,xueshanf/etcd,wantonsolutions/dinv-etcd,handsomesun/etcd,wowsoso/etcd,nieanan/etcd,cvik/etcd,devfreesg/etcd,nekto0n/etcd,bakins/etcd,handsomesun/etcd,giantswarm/etcd,hpcloud/etcd,sebrandon1/etcd,bluebreezecf/etcd,csuideal/etcd,gyuho/etcd,robszumski/etcd,coreos/etcd,gosharplite/etcd,jefby/etcd,ajityagaty/etcd,hongbinz/etcd,chai2010/etcd,armstrongli/etcd,xdlinear/etcd,tamird/etcd,combk8s/etcd,wantonsolutions/dinv-etcd,jmptrader/etcd,glensc/etcd,whuwxl/etcd,asim/etcd,sayden/etcd,lumjjb/etcd,zaphod-concur/etcd,giantswarm/etcd,tguangch/etcd,glevand/coreos--etcd,csuideal/etcd,tempbottle/etcd,fanminshi/etcd,wfxiang08/etcd,spotify/etcd,whuwxl/etcd,QuantiumTechnology/etcd,luxas/etcd,chenbaihu/etcd,sinsharat/etcd,junxu/etcd,YuleiXiao/etcd,princeqjzh/etcd,kingland/etcd,offscale/etcd,StorReduce/etcd,jravetch/etcd,mwitkow/etcd,chai2010/etcd,msanterre/etcd,spacejam/etcd,a-robinson/etcd,cvik/etcd,siddontang/etcd,pauldallen/etcd,njharman/etcd,raoofm/etcd,snailwalker/etcd,nkhare/etcd,hongchaodeng/etcd,pauldallen/etcd,glycerine/etcd,kkaneda/etcd,snailwalker/etcd,cvik/etcd,bakins/etcd,akauppi/etcd,gouyang/etcd,Ulexus/etcd,ravigadde/etcd,bluebreezecf/etcd,elimisteve/etcd,qqsun8819/etcd,youxidev/etcd,ecnahc515/etcd,xychu/etcd,rchicoli/etcd,pengzj/etcd,oscarrr110/etcd,sebschrader/etcd,delkyd/etcd,gouyang/etcd,shawnps/etcd,zaphod-concur/etcd,spotify/etcd,nekto0n/etcd,es-chow/etcd,improbable-io/etcd,dnaeon/etcd,mkumatag/etcd,xebitstudios/etcd,gosharplite/etcd,Yhgenomics/etcd,ravigadde/etcd,bdarnell/etcd,fasaxc/etcd,cognusion/etcd,cchamplin/etcd,mkumatag/etcd,vimalk78/etcd,lorneli/etcd,hroyrh/etcd,bspline/etcd,Winslett/etcd,etcd-io/etcd,shafreeck/etcd,elimisteve/etcd,fgbreel/etcd,visheshnp/etcd,ktateish/etcd,pengzj/etcd,kkaneda/etcd,cockroachdb/etcd,chenbaihu/etcd,lzbgt/etcd,gyuho/etcd,imzhulei/etcd,linuxcer/etcd,plasticbox/etcd,westhood/etcd,bspline/etcd,devfreesg/etcd,xebitstudios/etcd,betawaffle/etcd,achanda/etcd,fanminshi/etcd,HideoYamauchi/etcd,gae123/etcd,shafreeck/etcd,hongbinz/etcd,insionng/etcd,vimalk78/etcd,gityf/etcd,TheHippo/etcd,es-chow/etcd,cchamplin/etcd,westhood/etcd,yyljlyy/etcd,crandles/etcd,svdata/etcd,purpleidea/etcd,princeqjzh/etcd,beni55/etcd,Timer/etcd,iamqizhao/etcd,bdarnell/etcd,pigfoot/etcd,xdlinear/etcd,jonboulle/etcd,jchauncey/etcd,ylong/etcd,wantonsolutions/dinv-etcd,sayden/etcd,mqliang/etcd,polvi/etcd,insequent/etcd,akauppi/etcd,ylong/etcd,qiaochao911/etcd,crandles/etcd,msanterre/etcd,yichengq/etcd,Eagle-X/etcd,jravetch/etcd,robszumski/etcd,jchauncey/etcd,fasaxc/etcd,olark/etcd,luxas/etcd,combk8s/etcd,jlamillan/etcd,openedbox/etcd,gityf/etcd,delkyd/etcd,yudai/etcd,imzhulei/etcd,SivagnanamCiena/etcd,rnaveiras/etcd,mgoelzer/etcd-fork2,wowsoso/etcd,dnaeon/etcd,mwitkow-io/etcd,QuantiumTechnology/etcd,etcd-io/etcd,armstrongli/etcd,mqliang/etcd,mwitkow/etcd,StorReduce/etcd,li-ang/etcd,jlamillan/etcd,OyTao/etcd_learning,Ulexus/etcd,sinsharat/etcd,mickep76/etcd,glevand/coreos--etcd,oscarrr110/etcd,insionng/etcd,nieanan/etcd,chipironcin/etcd,axingblog/etcd,offscale/etcd,mwitkow-io/etcd,improbable-io/etcd,TheHippo/etcd,dalanlan/etcd,honeyqa/etcd,asim/etcd,mitake/etcd,steveeJ/etcd,jeremyeder/etcd,mkumatag/etcd,visheshnp/etcd,xiang90/etcd,chipironcin/etcd,beni55/etcd,swingbach/etcd,spotify/etcd,YuleiXiao/etcd,chai2010-playground/etcd,barakmich/etcd,mischief/etcd,glycerine/etcd,yichengq/etcd,endocode/etcd,Ulexus/etcd,cvik/etcd,axingblog/etcd,hzy001/etcd,mqliang/etcd