Fix ActionController::InvalidCrossOriginRequest errror

On production, "/entries.js" was resulting in ActionController::InvalidCrossOriginRequest...

I tried modifying the rack-cors gem as advised via the interwebs but still got
the same error. The only way I can get this to work is to NOT protect from
forgery on the index action. Everything is still under auth, so I think this is ok,
but let's discuss...