updated rails to 4.2.4

spec/factories/comments.rb

@@ -0,0 +1,9 @@
+# Read about factories at https://github.com/thoughtbot/factory_girl
+
+FactoryGirl.define do
+  factory :comment do
+    body 'Most interresting comment ever, created by a girl.'
+    user
+    association :commentable, factory: :event
+  end
+end

spec/factories/events.rb

@@ -47,6 +47,7 @@ FactoryGirl.define do
         event.difficulty_level = build(:difficulty_level, conference: event.conference)
         event.track = build(:track, conference: event.conference)
         event.room = build(:room, conference: event.conference)
+        event.comment_threads << build(:comment, commentable: event)
       end
     end