e2e: test /v3alpha,beta in v3 curl tests
e2e: test /v3alpha,beta in v3 curl tests

Signed-off-by: Gyu-Ho Lee <3454051ee3341eb69bdf6fca40899cdad4d86496@gmail.com>

mkumatag/etcd,sinsharat/etcd,dannysauer/etcd,mkumatag/etcd,whuwxl/etcd,etcd-io/etcd,ajityagaty/etcd,fanminshi/etcd,joshix/etcd,sinsharat/etcd,coreos/etcd,vimalk78/etcd,sebrandon1/etcd,coreos/etcd,bluebreezecf/etcd,heyitsanthony/etcd,rnaveiras/etcd,mqliang/etcd,mkumatag/etcd,xiang90/etcd,vimalk78/etcd,rnaveiras/etcd,bluebreezecf/etcd,sebrandon1/etcd,xiang90/etcd,etcd-io/etcd,joshix/etcd,li-ang/etcd,glevand/coreos--etcd,glevand/coreos--etcd,ajityagaty/etcd,rnaveiras/etcd,lorneli/etcd,bdarnell/etcd,gyuho/etcd,gyuho/etcd,dannysauer/etcd,mqliang/etcd,ajityagaty/etcd,etcd-io/etcd,heyitsanthony/etcd,cockroachdb/etcd,li-ang/etcd,mqliang/etcd,lorneli/etcd,bdarnell/etcd,whuwxl/etcd,fanminshi/etcd,cockroachdb/etcd