etcd: embed: Can't restart etcd

Etcd now has an embed API. Sweet 😃

I believe there is still a bind problem when starting a server, then stopping it, and then starting it again. On the second start, you’ll get a bind: address already in use error because the listen isn’t closed properly.

Opening this issue at the request of @heyitsanthony

I think this may be casually related to https://github.com/coreos/etcd/issues/2920

Thanks!