Upgrade to sbt 0.13.1.
Update dependencies so we can build against 2.11.0-M7

Update dependencies to version numbers that are published against
both 2.10 and 2.11.0-M7. This way we can release sbinary from master for
both 2.10 and 2.11.0-M7.
Merge pull request #11 from gkossakowski/2.11-compat-for-master

Update dependencies so we can build against 2.11.0-M7