Assets setup

Add React JS and Foundation. Also specified a Ruby version (for people using rbenv at least, not sure how it exactly works with rvm). Also removed the Coffeescript gem, because I think coffee -> jsx -> javascript would end up being kind of a mess. This hasn't caused any dependency problems for me, but not 100% sure on this one, so just let me know if this messes anything up.

React and Foundation  should "just work" after you install the gems