Travis claimed errors of gosimple like below
(https://travis-ci.org/coreos/etcd/jobs/208098545):
gosimple checking failed:
contrib/raftexample/raftexample_test.go:78:6: should write erri := <-clus.errorC[i] instead of erri, _ := <-clus.errorC[i]
contrib/raftexample/raftexample_test.go:114:10: should write err := <-eC instead of err, _ := <-eC
This commit fixes the errors.
Add a channel over which we can propose cluster config changes to
raft. In an upcoming commit we'll add an HTTP endpoint that sends config
changes over this channel.
deadlock if no leader; node selects on propc=nil and writes to Ready,
client blocks on propC in same select as Ready reader, and so progress
of raft state machine deadlocks.
Hitoshi Mitake