Update README.md

Added:
* [Unit Testing w/ AngularJS] (http://moduscreate.com/unit-testing-w-angularjs/)
* [Leverage Scope Creep! An in-depth tutorial on Angular.js Scope] (http://modernweb.com/2014/07/14/leverage-scope-creep-depth-tutorial-angular-js-scope/)
* [Rethinking AngularJS Controllers] (http://toddmotto.com/rethinking-angular-js-controllers/)
* [AngularJS: "Controller as" or "$scope"?] (http://codetunnel.com/angularjs-controller-as-or-scope/)
* [AngularJS’s Controller As and the vm Variable] (http://www.johnpapa.net/angularjss-controller-as-and-the-vm-variable/)