Bootstrap Angular testing

I don't know if there's any desire to have this, but I thought it might be useful for the project as I've found getting started with Angular testing on mocha to be a pain.

* Updated README with information pertaining to testing
* Bump Angular version to include a compatible version of angular-mocks

     ** The latest version of angular-mocks does not support mocha, however
         it is in the pipeline (https://github.com/angular/angular.js/commit/92558fe4119fb1ee793d781de1888abef181c7f6)
     ** Because there is no release yet, angular-mocks was manually dropped in public/js/vendor/ until 1.2.x is released (next stable release)
* Add a simple test for the articles controller