Updated build dependencies as com.google.code.guice is no longer availab...

This explains the sbt bug we're working around:
https://groups.google.com/forum/#!msg/simple-build-tool/fq7bJnOd9SM/XJJPFsteas8J

Issue on openid4java opened here:
http://code.google.com/p/openid4java/issues/detail?id=188