still have debugging stuff in this commit. it's currently rendering the image so I can check output
It doesn't seem to be responding to the event, and it's stopped hiding the UI elements around the edge
Added worker process to call the phantomjs script in app/workers
Added hook in models/map.rb to call the worker
Added calls to map.touch in mappings_controller.rb so it would get triggered correctly - I'm not sure how this will proceed moving forward
