Oh, hello! Vellum has js tests; how about replicating this for HQ?

The operative files are:

 - https://github.com/dimagi/Vellum/blob/master/js/tests/formdesigner.spec.js
 - https://github.com/dimagi/Vellum/blob/master/js/tests/runner.html
 - https://github.com/dimagi/Vellum/blob/master/.travis.yml

(There are other files that sound test-like but I think they are dead code)