Completed initial REST API.

Added user put endpoint.

Added a user post endpoint.

Added proper status return to user controller.

Added user schema and migrations.

Added user#show endpoint

Added user#show endpoint

Add a static model to support the users endpoint.

Added hard-coded /users endpoint.

This change involved adding a route for the /users endpoint and creating
a user controller. This controller now returns hard-coded JSON data.

Initial commit of base Phoenix project.