e2e: Test case for the etcdctlv3 'role grant' command.
e2e: Test case for the etcdctlv3 'role grant' command.

Adding a test case to test the 'role grant' sub-command.

ajityagaty/etcd,lorneli/etcd,wantonsolutions/dinv-etcd,bdarnell/etcd,glycerine/etcd,whuwxl/etcd,coreos/etcd,lumjjb/etcd,yudai/etcd,ktateish/etcd,visheshnp/etcd,StorReduce/etcd,joshix/etcd,achanda/etcd,joshix/etcd,lorneli/etcd,tguangch/etcd,chipironcin/etcd,sinsharat/etcd,fanminshi/etcd,armstrongli/etcd,mqliang/etcd,mqliang/etcd,coreos/etcd,wantonsolutions/dinv-etcd,sofuture/etcd,xiang90/etcd,ravigadde/etcd,visheshnp/etcd,endocode/etcd,etcd-io/etcd,akauppi/etcd,heyitsanthony/etcd,handsomesun/etcd,OyTao/etcd_learning,lumjjb/etcd,CrazyJvm/etcd,jonboulle/etcd,ajityagaty/etcd,li-ang/etcd,OyTao/etcd_learning,westhood/etcd,rnaveiras/etcd,etcd-io/etcd,dannysauer/etcd,wantonsolutions/dinv-etcd,yudai/etcd,handsomesun/etcd,mkumatag/etcd,jlamillan/etcd,a-robinson/etcd,plasticbox/etcd,etcd-io/etcd,nekto0n/etcd,gyuho/etcd,bdarnell/etcd,swingbach/etcd,vimalk78/etcd,cockroachdb/etcd,luxas/etcd,rnaveiras/etcd,gyuho/etcd,achanda/etcd,mqliang/etcd,glycerine/etcd,bluebreezecf/etcd,zaphod-concur/etcd,glevand/coreos--etcd,sebrandon1/etcd,sebrandon1/etcd,CrazyJvm/etcd,bluebreezecf/etcd,hongchaodeng/etcd,luxas/etcd,mickep76/etcd,sofuture/etcd,nekto0n/etcd,chipironcin/etcd,tguangch/etcd,hongchaodeng/etcd,rchicoli/etcd,swingbach/etcd,jlamillan/etcd,ktateish/etcd,ajityagaty/etcd,ravigadde/etcd,YuleiXiao/etcd,YuleiXiao/etcd,StorReduce/etcd,plasticbox/etcd,akauppi/etcd,endocode/etcd,qqsun8819/etcd,armstrongli/etcd,glevand/coreos--etcd,mickep76/etcd,xiang90/etcd,purpleidea/etcd,qqsun8819/etcd,dnaeon/etcd,whuwxl/etcd,zaphod-concur/etcd,cockroachdb/etcd,insequent/etcd,li-ang/etcd,insequent/etcd,a-robinson/etcd,dnaeon/etcd,sinsharat/etcd,vimalk78/etcd,heyitsanthony/etcd,jonboulle/etcd,mkumatag/etcd,mkumatag/etcd,rnaveiras/etcd,westhood/etcd,linuxcer/etcd,dannysauer/etcd,fanminshi/etcd,rchicoli/etcd,linuxcer/etcd,purpleidea/etcd