Start Gollum via Rack

Question

I am new to Ruby and Rack. I found a project called Gollum. I want to set the Author and followed this instruction. I installed it via gem install gollum. But when I want to start the project via:

/gollum/config.ru

the commandline tells me undefined method 'run' for main:Object.

My config.ru looks like this:

#!/usr/bin/env ruby
require 'rubygems'
require 'gollum/app'

module Precious
  class App < Sinatra::Base
    ['/create/*','/edit/*'].each do |path|
      before path do

        session['gollum.author'] = {:name => "xxx",
                                :email => "xxx"}
      end
    end
  end
end

run Precious::App

Can somebody give me a hint?