Feature #67989550 User sign up
-Add user sign up functionality
-Add Devise
-Add feature spec
-Add User model spec
Feature #68248378 User login
-Add sign_in spec
-add sign_in_spec
-add login link to header
Feature #68248560 User logout
-Add Log out link to header
-Add sign_out_spec
Feature #68321634 Admin login
-Add Role model and UserRole join table
-add has_many_through association
-Add redirect to Admin Dashboard when admin logs in