Merge pull request #15 from xiangli-cmu/master

Fix leader field and delete some redundant codes
Clean up API.
Merge branch 'master' of https://github.com/benbjohnson/go-raft
LICENSE: initial commit

The README.md file mentions the MIT license but just to make it clear
put a copy of the LICENSE in the repo.
Merge pull request #16 from philips/master

LICENSE: initial commit
Track current leader.
Merge branch 'master' of https://github.com/benbjohnson/go-raft
Add Server.LastCommandName().
Fix timer race condition.
Fix peer timer race condition.
Serialize election timeout goroutine.
solve conflicts