8.1.1  add Sessions controller and setup signin/signout routes
8.1.2  create sign-in tests
8.1.3  create login form
8.1.4 and 8.1.5  reviewing form submission and flash message
8.2.1  add remember token
8.2.2  add sign_in method to SessionsHelper
8.2.3  add methods to get and set current_user
8.2.4  update views depending on signin status
8.2.5  after sign-up automatically signin the user
8.2.6  implement signout functionality
8.3.2  add cucmber tests
8.3.3  Adding a helper method and a custom RSpec matcher