Merge pull request #217 from phlipper/fix-sinatra-api-warning

set :public_folder in frontend app instead of :public

lib/gollum/frontend/app.rb

@@ -13,8 +13,7 @@ module Precious
     dir = File.dirname(File.expand_path(__FILE__))
 
     # We want to serve public assets for now
-
+    set :public_folder, "#{dir}/public"
-    set :public,    "#{dir}/public"
     set :static,         true
 
     set :mustache, {