add Admin model
sample User specs adn additional validation for username
set test mailer to localhost
add Admin blueprint, extend User
add validation specs for User
add User#admin?
add DaschboardController for User
redirect users based on type (Admin to backend)
prepare admin dashboard for bootstrap
add ControllerHelpers module for devise/sign_in
add DashboardController specs for Admin and User
preparing future steps: move backend auth to BaseController
simple view specs for dashboard
Merge branch 'feature/add_admin' into develop