Scalafmt configuration

Scalafmt configuration comes along with the codacy-sbt plugin.

The plugin defines a taskKey for genrating it:

sbt genScalafmtConfig

and it rely on a settingKey to know what to do in case of a pre-existing file:

forceScalafmtConfigRewrite

By setting it within the SBT interactive shell you can easily perform the upgrade to a new version of the scalafmt configuration.