WIP: Functional tests

Fixes #25.

- [x] Setup intern
- [x] Test unauthenticated index
- [x] Test sign in
- [x] Create mock device that responds to commands
- [x] Bootstrapping script (Phony bootstraps itself by inserting records into the db)
- [x] Test ring
- [x] Test lock
- [x] Test erase
- [x] Extract constants
- [x] Add tests/* directory to JSHint/JSCS Grunt paths
- [x] ~~Attempt to make tests DRYer with `before` and `after` functions.~~ (optimization for follow up PR)
We tend to use plurals for most other directories (images, scripts, styles, etc), so I'll change everything to `tests`.