Add support for Scala 2.11

* Scala 2.11 support requires the latest Play 2.3 RC1.
* Upgrade Scala 2.10 to use latest Play 2.2.x (2.2.3).
* Upgrade scalatest to a version supporting Scala 2.11.
* Drop support for Scala 2.9.x - the dependencies don't resolve,
  and I couldn't find suitable replacements.
Fix deprecation warning

SimpleRequest -> Request
Merge pull request #10 from ProjectFlorida/scala-2.11

Scala 2.11