GH-1 - Updates HikariCP to version 1.3.8

Also, as suggested by @brettwooldridge, replaces
the property `minimumPoolSize` with `minimumIdle`.
GH-1 - Updates play version to 2.2.3
GH-1 - Bumps version to 1.1.0
GH-1 - Changelog for released versions
GH-1 - Adds info about which versions of hikari and play are used.

Closes #1