Implement end-to-end testing

@settinghead Wrote some tests for the alignment component. I'm wondering if there's a better way to organize these tests such that each one is self-describing. I've got some commenting in there that should really be output when the tests are run. For example, should the tests for opening the drop-down and clicking on the justify button each have their own casper.test.begin? Thx.

@stulees FYI.