E2E Atom integration

• Live progress of E2E test script runs, with line-by-line highlighting.
• Pause, resume, and cancel scripts directly from the editor (via menu, control key, or right-click).
• Automatically connects to any running E2E Application (via socket.io on localhost:4333)

Upcoming

• Set 'breakpoints' via the Atom editor so that scenarios can be paused and resumed at particular points in each scenario.