Pitaya v2.0.4 with dependency updates and some small improvements

Pitaya v1.1.9 with dependency updates and some small improvements

Pitaya v2.0.3 with some bug fixes and small improvements

Pitaya v2.0.2 with some bug fixes and small improvements

Only advertise server once initial sync is finished

Merge pull request topfreegames#172 from topfreegames/fixbugs

Fix metric tags, etcd reconnect, improve nats shutdown handling and logging

Merge pull request topfreegames#170 from topfreegames/update_deps

Update several dependencies

Merge pull request topfreegames#163 from topfreegames/feature/add-is-…

…running-method

Add `IsRunning` function to the `pitaya.Pitaya`

Merge pull request topfreegames#157 from topfreegames/feature/v2-appl…

…y-master-changes

Apply master (v1) latest version to v2

fix TestBeforeHandler test