8.1.1 generate session controllers
8.1.2 red signin tests
8.1.3 generate signin form with form_for
8.1.4 define create method with controller for form submission
8.1.5 green flash message for signin
8.2 define controller for signin success
8.2.1 green remember token
8.2.2 set cookies for sign in method
8.2.3 create method for finding current user using cookies only if undefined
8.2.4 green layout links
8.2.5 green signout link upon signup and route sign in within user creation
8.2.6 green authentication machinery