Add precompiled assets for Heroku
Set up signin failure
Fix flash message to show only on rendered page and not upon redirect
Add tests for signin success
Provide access to SessionsHelper to controllers; abtract signup success
Plant a CSRF safeguard (sign_out not defined yet)
Add remember_token to User
Add create_remember_token functionality to User
Add signin, setter, and getter methods for current user
Complete signin and signout functionality
Add test for signout
Set automatic signin upon signup