etcdserver: enhance test cases for isReadyToAddNewMember
etcdserver: enhance test cases for isReadyToAddNewMember

 - a case of a cluster with even number members
 - a case of an empty cluster

purpleidea/etcd,rnaveiras/etcd,dnaeon/etcd,rnaveiras/etcd,sayden/etcd,armstrongli/etcd,yichengq/etcd,CrazyJvm/etcd,Eagle-X/etcd,etcd-io/etcd,HideoYamauchi/etcd,etcd-io/etcd,mkumatag/etcd,YuleiXiao/etcd,fgbreel/etcd,vimalk78/etcd,combk8s/etcd,beni55/etcd,a-robinson/etcd,pauldallen/etcd,bdarnell/etcd,combk8s/etcd,xychu/etcd,rnaveiras/etcd,achanda/etcd,gae123/etcd,heyitsanthony/etcd,tamird/etcd,sofuture/etcd,lorneli/etcd,insequent/etcd,pauldallen/etcd,jlamillan/etcd,CrazyJvm/etcd,shawnps/etcd,bdarnell/etcd,coreos/etcd,whuwxl/etcd,handsomesun/etcd,fanminshi/etcd,a-robinson/etcd,jchauncey/etcd,mike-lerch/etcd,hongchaodeng/etcd,vimalk78/etcd,Winslett/etcd,mike-lerch/etcd,asim/etcd,Timer/etcd,cockroachdb/etcd,ktateish/etcd,visheshnp/etcd,lumjjb/etcd,iamqizhao/etcd,dannysauer/etcd,plasticbox/etcd,wowsoso/etcd,msanterre/etcd,bluebreezecf/etcd,glycerine/etcd,shawnps/etcd,luxas/etcd,rchicoli/etcd,gouyang/etcd,sofuture/etcd,nekto0n/etcd,armstrongli/etcd,cockroachdb/etcd,zaphod-concur/etcd,li-ang/etcd,jonboulle/etcd,visheshnp/etcd,jlamillan/etcd,heyitsanthony/etcd,fasaxc/etcd,Eagle-X/etcd,li-ang/etcd,sebrandon1/etcd,glevand/coreos--etcd,hongbinz/etcd,improbable-io/etcd,xychu/etcd,insequent/etcd,sebrandon1/etcd,endocode/etcd,tamird/etcd,jchauncey/etcd,joshix/etcd,gouyang/etcd,tguangch/etcd,beni55/etcd,xdlinear/etcd,swingbach/etcd,zaphod-concur/etcd,qqsun8819/etcd,chipironcin/etcd,oscarrr110/etcd,coreos/etcd,hongchaodeng/etcd,StorReduce/etcd,westhood/etcd,westhood/etcd,oscarrr110/etcd,siddontang/etcd,raoofm/etcd,wantonsolutions/dinv-etcd,OyTao/etcd_learning,ajityagaty/etcd,wantonsolutions/dinv-etcd,gyuho/etcd,kkaneda/etcd,fgbreel/etcd,akauppi/etcd,luxas/etcd,linuxcer/etcd,mqliang/etcd,jonboulle/etcd,mkumatag/etcd,qqsun8819/etcd,improbable-io/etcd,achanda/etcd,jeremyeder/etcd,sinsharat/etcd,ravigadde/etcd,iamqizhao/etcd,TheHippo/etcd,wantonsolutions/dinv-etcd,xiang90/etcd,purpleidea/etcd,endocode/etcd,fanminshi/etcd,nekto0n/etcd,ktateish/etcd,yichengq/etcd,cchamplin/etcd,cchamplin/etcd,kkaneda/etcd,whuwxl/etcd,asim/etcd,giantswarm/etcd,tguangch/etcd,gae123/etcd,yudai/etcd,yudai/etcd,dannysauer/etcd,sayden/etcd,etcd-io/etcd,YuleiXiao/etcd,hroyrh/etcd,dnaeon/etcd,mqliang/etcd,linuxcer/etcd,handsomesun/etcd,bluebreezecf/etcd,fasaxc/etcd,StorReduce/etcd,HideoYamauchi/etcd,gyuho/etcd,joshix/etcd,plasticbox/etcd,lorneli/etcd,chipironcin/etcd,lumjjb/etcd,ravigadde/etcd,mickep76/etcd,xiang90/etcd,xdlinear/etcd,jeremyeder/etcd,hroyrh/etcd,hongbinz/etcd,siddontang/etcd,wowsoso/etcd,sinsharat/etcd,mkumatag/etcd,giantswarm/etcd,OyTao/etcd_learning,akauppi/etcd,ajityagaty/etcd,Winslett/etcd,Timer/etcd,fasaxc/etcd,rchicoli/etcd,glycerine/etcd,glevand/coreos--etcd,mqliang/etcd,TheHippo/etcd,raoofm/etcd,swingbach/etcd,mickep76/etcd,msanterre/etcd,ajityagaty/etcd