cm: Replace Grunt/RequireJS with Gulp/Browserify. Yes, I know, this sounds like it's 2014 or something, and cool kids are now actually on webpack or whatever. Anyway, besides the change to a `gulpfile`, it also moves all dependencies over to `npm` (via the `package.json` file), which cleans up the repository nicely, and replaces awkward JS imports with simpler `require` statements.

sudo: false
language: python
python:
  - "3.4"
  - "3.5"
  - "3.6"
install:
  - "pip install -r requirements.txt"
  - "pip install -r dev-requirements.txt"
script: py.test