Introduce `sbt-release` plugin.
Set appVersion `0.2.1`.
Setting version to 0.2.1
Setting version to 0.2.2-SNAPSHOT
Update Play to version `2.2.2`.
Remove unused dependencies in `Build`.
Fix tests.
Change `SecureUser.id` from `Option[Int]` to `Int`.
Remove `ensime-sbt-cmd` plugin.
Replace the old `Build.scala` file with the new `build.sbt`.