FEATURE: Allow admins to lock users from TL3 promotion/demotion

Also, update the display logic for the leader promotion screen to
account for the demotion grace period.

app/serializers/trust_level3_requirements_serializer.rb

@@ -1,6 +1,8 @@
 class TrustLevel3RequirementsSerializer < ApplicationSerializer
   attributes :time_period,
              :requirements_met,
+             :requirements_lost,
+             :trust_level_locked, :on_grace_period,
              :days_visited, :min_days_visited,
              :num_topics_replied_to, :min_topics_replied_to,
              :topics_viewed, :min_topics_viewed,
@@ -19,4 +21,8 @@ class TrustLevel3RequirementsSerializer < ApplicationSerializer
   def requirements_met
     object.requirements_met?
   end
+
+  def requirements_lost
+    object.requirements_lost?
+  end
 end