Add feature, controller, and model tests for passing a turn

Switch Capybara driver to Poltergeist
Add wait_until helper to Capybara to handle websocket initial connection delay
Add ActiveRecord patch to ensure db transactions behave during Capybara tests
Implement turn passing functionality

Add pass button that submits via AJAX
Use existing update publishing framework via Redis -> Node -> browser
Also create games view helper for displaying header status message
Add sending of 'update received' message to Node server

Fix integer/string bug for js move_num var (wasn't causing problems?!)
Merge branch 'add-turn-passing'