putting checkstyle configuration outside executions
Merge pull request #174 from fengjingchao/master

putting checkstyle <configuration> outside <executions>
Raise exception if send request in non-broadcasting phase.
Fix the bug of SimpleLog found in jepsen test.
Optimization on FastLeaderElection.

1. Everybody broadcasts its own vote at beginning.
2. Don't clear message queue when participants go back to recovery case
since it might remove election messages.
Move the handling of query leader message after heartbeat check.

Found it by running jepsen test.
Fix the timeout bug in jepsen test.
Merge pull request #172 from EasonLiao/raise_exception

Don't buffer the request in non-broadcasting phase.
Bump version to 0.2.0-SNAPSHOT.
Fix publish-artifacts.sh.

- Run the script with -e option so that the build fails if the script
  fails.
- Push javadoc for all the branches.
- Update git repo url.