Save syndication sources to posts

spec/support/factories/posts.rb

@@ -0,0 +1,7 @@
+Test::Factory.define(:post) do |f|
+  f.name "post_name"
+  f.content "post_content"
+  f.slug "post-slug"
+  f.published_at Time.now
+  f.syndication_sources {}
+end