Setup testing; add request spec for homepage.

Also:
  * Install and use Capybara
  * Install and initialise Guard
  * add haml-rails.
Create user model.
Add email attribute validation to User model.
Start users/new request spec.

Also add 'has_secure_password' method to User, but unable to test
validaton, so moving to request spec to proceed.
Add formating to rspec in Guardfile.
Add password field to new user form.
Add password confirmation field to new user form.
Add user create and show actions.
Add note to write User controller spec.
Add invalid data handling to new user form.
Add users controller spec.
Add Factories for Users
Fix User factory and request spec
Fix invalid User create test
Add sessions controller
Completed basic login features