Add functional tests

[lavelle]

We currently have a pretty good unit test suite for the two providers, that tests each of the FSP events as well as the wrapper classes and utility functions. However, now that a UI is being added, it would be good to have some tests to verify the overall behaviour of the system.

For regular webapps there are tools like Selenium Webdriver, but I've never used anything like that I don't whether it would work with a Chrome packaged app. We need an environment with the chrome.* APIs for testing (unless we mocked them in the browser?)

Options that won't work

• Zombie: uses JSDOM which doesn't have the features Polymer needs
• Casper: uses Phantom which doesn't have the features Polymer needs
• Selenium WebDriver: Introduces Java dependency
• Dalek: can drive Chrome, but is in developer preview and therefore not suitable for a production app

Still to try

• The Intern
• Sauce Labs

[jmuk]

I have little ideas here. For now UI is simple enough to be tested through unit tests, Selenium is an overkill.

[lavelle]

CasperJS looks like a good choice. It runs in PhantomJS, which we already use, and has a Grunt plugin. It's also pure JS, so there's no Java dependency like Selenium.

Admittedly, this might be a bit premature given how simple the UI is right now, but might be worth considering further down the road.