Monkeypatch relations into Publify Blog model

monkeypatch.diff

diff --git a/config/initializers/model_extensions.rb b/config/initializers/model_extensions.rb
new file mode 100644
index 000000000..2db532ba9
--- /dev/null
+++ b/config/initializers/model_extensions.rb
@@ -0,0 +1 @@
+require "blog_extension"
diff --git a/lib/blog_extension.rb b/lib/blog_extension.rb
new file mode 100644
index 000000000..01fbcf5b3
--- /dev/null
+++ b/lib/blog_extension.rb
@@ -0,0 +1,9 @@
+module BlogExtension
+  extend ActiveSupport::Concern
+
+  included do
+    has_many :xyz
+  end
+end
+
+Blog.include BlogExtension