Starting point of tests using BDD

Added:
* Test environment config
  * **see:** database connection uri for credential details
* Test for the `/healthcheck` route
* New devDependencies for testing
  * [grunt-mocha-test](https://github.com/pghalliday/grunt-mocha-test)
  * [chai](http://chaijs.com)
  * [supertest](https://github.com/visionmedia/supertest)

Changed:
* `grunt test` task now runs **all** mocha tests in `/test`
* Travis config now includes mysql service.