Listing 8.17: add test for remember token
8.2.1: create a remember token method added
8.2.2: sessions helper to make cookies
8.2.3: session helper to find the current user
Listing 8.24: changed header to reflect signin options
8.2.4: added sessions page for logged in users
Listing 8.26: spec to test that newly signed-up users are also signed in
8.2.5: signin the user upon signup
8.2.6: added Signout