Finish sec 7.1 Showing users
Finished 7.2.1, start 7.2.2 Using form_for
Finished 7.2.2
Finished 7.3.1, start 7.3.2 Strong parameters
Finished 7.3.2, start 7.3.3 Signup error messages
Finished 7.3.3, start 7.4 Signup success
Updated CSS for the error segment to look better
Finished 7.4.2, start 7.4.3