Merge branch 'followed' into 'master'

Followed

See merge request !435

app/serializers/collection_serializer.rb

@@ -14,7 +14,7 @@ class CollectionSerializer < ActiveModel::Serializer
   end
 
   def followed
-    object.followed? current_user
+    current_user.try(:following?, object)
   end
 
   def items_thumbnails

app/serializers/user_serializer.rb

@@ -6,7 +6,7 @@ class UserSerializer < ActiveModel::Serializer
   end
 
   def followed
-    object.followed? current_user
+    current_user.try( :following?, object)
   end
 
   def email