Update sbt-rc to 8b254f8e0016c0ad28423dcf03ebd0fc9c27e501

This is supposed to fix console incompatibility with newer akka/play
Merge pull request #282 from typesafehub/wip/havocp-sbt-rc-update

Update sbt-rc to 8b254f8e0016c0ad28423dcf03ebd0fc9c27e501