Add simple user authentication
* User model with has_secure_password
* Each article or comment is owned by a user
* Any user may view articles/comments
* Only the article or comment's owner may edit or destroy the object
Install test gems, set up rspec, add first test
Add data mocking gems and write simple test using mocked data
* Add DatabaseCleaner, FactoryGirl, Faker
* Write a simple test to ensure articles are correctly displayed
Add complete feature test suite
* Sign up, log in, log out users
* Create, edit, destroy articles
* Create, destroy comments
* Session feature test helper methods