Add Scala style plugin to project

[grahamcrowell]

This enforces naming conventions and other best practices with warnings in IDE at compile time.

I think u just add it sbt file.

[grahamcrowell]

http://www.scalastyle.org/configuration.html

[grahamcrowell]

how to configure: http://www.scalastyle.org/sbt.html

scala style docs: http://docs.scala-lang.org/style/