Maintenance banner moved to admin site (#1775)

* initial

* finish

* travis fixes

* travis again

* not required

app/helpers/theming_helper.rb

@@ -36,4 +36,8 @@ module ThemingHelper
   def user_color
     @settings.get_value("Primary Color") || Rails.configuration.primary_color_default
   end
+
+  def maintenance_banner
+    @settings.get_value("Maintenance Banner")
+  end
 end