add tests

@stevestreza I'd really appreciate if you'd look this over, and modify it how you like. I made a buncha tests that have been useful in refining the current DevCenter.me sites. However, both Travis and Digital Ocean should be modified to work with the Mocha tests.

In testing myself, I kinda abandoned `test-sites.js` as it was slow and prone to breakage. I think synchronous automated testing really isn't the way to do things in this case (but maybe I'm wrong).