add more CRUD methods to Model protocol
+ all these methods should be implemented by all model resources
update user#new route to accept a phone-uuid, rather than an "id"
+ "id" didn't seem descriptive enough
update main_test/with-server to handle exceptions better

+ system was not being shutdown when an exception occurred
major refactoring of main_test

+ organize code better with headings
+ create helpers for making user-specific endpoint requests and handling responses
+ add a single test for create and loading a new user
major refactoring of models.user namespace

+ add helpers for loading users from redis
+ update responses for user#new & user#show