UX: Slightly improved reviewable user display, plus link to admin if possible

app/serializers/reviewable_user_serializer.rb

@@ -1,9 +1,15 @@
 class ReviewableUserSerializer < ReviewableSerializer
 
+  attributes :link_admin
+
   payload_attributes(
     :username,
     :email,
     :name
   )
 
+  def link_admin
+    scope.is_staff? && object.target.present?
+  end
+
 end