etcd: attach default scheme to the peer-list if scheme is not given
Merge pull request #29 from etcd-team/etcd_empty_scheme

etcd: attach default scheme to the peer-list if scheme is not given
raft: add clusterId to snapshot
Merge pull request #49 from etcd-team/snap

raft: add clusterId to snapshot
server: use random generated node id
Merge pull request #43 from etcd-team/fix-id

server: use random generated node id
server: add testCluster.Add

and fix possible testing error.