Changes to configuration, server, and client

I spent some time locking gem versions and building a deployable configuration. It seems that with the right versions of the gems and good naming, we don't need to manually move files.

Some of the gems are tricky, for example Spree 2.2.2 is not compatible with rails 4.0.9, so the development Gemfile reflects that.

On the backend, I added a new controller method and a model method that will query the server and return the current state of the invoice.

The javascript changes employ a timeout to continuously poll the server.

I have tested these changes locally and on a test_net server (50.116.35.154) where this code is currently running.