Finish 8.1.1 Sessions controller
Finish 8.1.2 Signin tests
Finish 8.1.3 Signin form
Finish 8.1.4 Reviewing form submission
Finish 8.1.5 Rendering with a flash message
Finish 8.2.1 Remember me
Finish 8.2.2 A working sign_in method
Finish 8.2.3 Current user
Finish 8.2.4 Changing the layout links
Finish 8.2.5 Signin upon signup
Finish 8.2.6 Signing out, also fixed a misplace 'end' that was causing failing tests.