This introduces two new concepts: the cluster and the member.
Members are logical etcd instances that have a name, raft ID, and a list
of peer and client addresses.
A cluster is made up of a list of members.
Using 0xBEEF is annoying in examples because it makes it makes it look
like the user can use ascii or something. In the Procfile use
0x0,0x1,0x2,etc and use 0xBAD0 in test.