Require 'github/markup' in Gemfile

Gemfile

@@ -57,7 +57,7 @@ gem "seed-fu"
 
 # Markdown to HTML
 gem "redcarpet",     "~> 2.1.1"
-gem "github-markup", "~> 0.7.4"
+gem "github-markup", "~> 0.7.4", require: 'github/markup'
 
 # Servers
 gem "thin"

app/controllers/refs_controller.rb

-require 'github/markup'
-
 class RefsController < ApplicationController
   include Gitlab::Encode
   before_filter :project