Add integration tests to ensure browser compatability

[ozzyogkush]

Currently we run unit tests on the source code, but not integration in a browser environment on the generated file.

Tasks

• Research what kind of CI system we can use for free that hooks into GitHub, and what environments (OS/Browser) we can test in
• Research for an integration test system that works with Grunt and allows for multiple environments
• Build integration tests and Grunt task that cover required in-browser use
• Include integration tests in the Grunt test task