Delay a little longer after starting sim node (#879)
Delay a little longer after starting sim node (#879)

- To make travis check more stable
jjlee9/openthread,openthread/openthread,pvanhorn/openthread,fbsder/openthread,librasungirl/openthread,gandreello/openthread,xiaom-GitHub/openthread,erja-gp/openthread,jwhui/openthread,librasungirl/openthread,jwhui/openthread,abtink/openthread,vaas-krish/openthread,chshu/openthread,GiedriusM/openthread,nibanks/openthread,pvanhorn/openthread,abtink/openthread,mszczodrak/openthread,JakubBrachTieto/openthread,Zolertia/openthread,openthread/openthread,aeliot/openthread,openthread/openthread,georgecpr/openthread,pvanhorn/openthread,JakubBrachTieto/openthread,georgecpr/openthread,JakubBrachTieto/openthread,LeZhang2016/openthread,vaas-krish/openthread,chshu/openthread,GiedriusM/openthread,gandreello/openthread,aeliot/openthread,jjlee9/openthread,georgecpr/openthread,openthread/openthread,fbsder/openthread,mszczodrak/openthread,jjlee3/openthread,mszczodrak/openthread,GiedriusM/openthread,vaas-krish/openthread,nibanks/openthread,fbsder/openthread,JakubBrachTieto/openthread,GiedriusM/openthread,LeZhang2016/openthread,pvanhorn/openthread,erja-gp/openthread,fbsder/openthread,fbsder/openthread,JakubBrachTieto/openthread,jjlee9/openthread,abtink/openthread,srickardti/openthread,srickardti/openthread,lanyuwen/openthread,Zolertia/openthread,jjlee9/openthread,bukepo/openthread,lanyuwen/openthread,aeliot/openthread,georgecpr/openthread,Zolertia/openthread,chshu/openthread,jjlee3/openthread,srickardti/openthread,mszczodrak/openthread,xiaom-GitHub/openthread,turon/openthread,aeliot/openthread,nibanks/openthread,bukepo/openthread,srickardti/openthread,jjlee9/openthread,georgecpr/openthread,turon/openthread,gandreello/openthread,Zolertia/openthread,chshu/openthread,GiedriusM/openthread,bukepo/openthread,aeliot/openthread,abtink/openthread,erja-gp/openthread,gandreello/openthread,georgecpr/openthread,jjlee3/openthread,turon/openthread,gandreello/openthread,librasungirl/openthread,mszczodrak/openthread,bukepo/openthread,vaas-krish/openthread,Zolertia/openthread,jwhui/openthread,pvanhorn/openthread,LeZhang2016/openthread,chshu/openthread,librasungirl/openthread,jjlee3/openthread,gandreello/openthread,erja-gp/openthread,lanyuwen/openthread,LeZhang2016/openthread,chshu/openthread,xiaom-GitHub/openthread,xiaom-GitHub/openthread,aeliot/openthread,xiaom-GitHub/openthread,nibanks/openthread,lanyuwen/openthread,jwhui/openthread,fbsder/openthread,mszczodrak/openthread,JakubBrachTieto/openthread,turon/openthread,xiaom-GitHub/openthread,jjlee3/openthread,lanyuwen/openthread,vaas-krish/openthread,vaas-krish/openthread,LeZhang2016/openthread,lanyuwen/openthread,jjlee9/openthread,erja-gp/openthread,nibanks/openthread,LeZhang2016/openthread,erja-gp/openthread,pvanhorn/openthread,nibanks/openthread