Add gulp tasks and style tests
Fix code linting issues, mostly
Remove raw test runner and future-proof test file names
Add linter/testing info to README
Run tests on Travis, at least in Linux environment

For now, we can at least run the tests and linters somewhere,
so here's a Travis file that should run them on Linux. (#8)
Remove leftover in style guide

Mostly just pushing to test travis ^_^
Merge pull request #12 from mozilla/gulp

Add gulp tasks and style tests