Add a User Repository & Controller

* Added a HomeController to test the web application is reachable.
* Added a User domain and User Repository for CRUD operations for User.
* Added a User Controller to expose User CRUD operations using
  REST-HATEOAS.
* Integrations tests for all.
Merge pull request #2 from bufferworks/topic/dewang/user-data-rest

Add a User Repository & Controller - Ship it!