Generate Sessions controller and authentication_pages integration test.
Modify authentication_pages_spec.rb with updated integration test(s).
Add sessions controller, new session view, and update routes.rb file.
Update integration tests for signin.
Update new session (signin) view.
Add action for sessions_controller create and fix typo in sessions/new.html.erb view file.
Update sessions_controller and associated tests.
Complete sign in functionality.
Finish sign in