Create Admin model with email validation
Add uniqueness contraint to admin email address
Add password and password confirmation through has_secure_password
Failed admin log in results in proper error notice
Add specs for authenticate method from has_secure_password
Create specs for working admin login
add jquery_ujs to application.js to enable javascript backed 'delete' links
Admins can now log into site
Admins can both log in and log out
Prevent access to admin homepage unless logged in