Upgrade stuff

A couple little things:  first, upgrade Ruby to 2.1.1 (I didn't feel like installing 2.1.0 :smile:); also there's debugger 1.6.6(!) now, which builds on 2.1.1, so upgrade to that!

Second, this repo currently comes without app/assets/javascripts/{controllers,views,helpers}, and git won't commit empty directories.  I believe the convention is to add a .keep file to the empty dir such that git will commit the directory.