refactored comments_controller tests; fixed access to Administration link into user_menu view

app/models/ability.rb

@@ -94,6 +94,7 @@ class Ability
     signed_in_with_volunteers_coordinator_role(user) if user.has_role? :volunteer_coordinator, :any
 
     # for users with any role
+    can :access, Admin
     can [:show], Conference
     can :index, Commercial, commercialable_type: 'Conference'
     cannot [:edit, :update, :destroy], Question, global: true

app/views/layouts/_user_menu.html.haml

@@ -21,10 +21,7 @@
     = link_to(destroy_user_session_path, :method=>'delete') do
       %span.fa.fa-minus
       Sign out
-- if current_user.is_admin || (current_user.has_any_role? :admin, { :name => :organizer, :resource => :any },
-                                                          { :name => :cfp, :resource => :any },
-                                                          { :name => :info_desk, :resource => :any },
-                                                          { :name => :volunteer_coordinator, :resource => :any })
+- if can? :access, Admin
   %li.divider
     %li
       = link_to(admin_conference_index_path()) do