title: toy/doc undefined method 'available?'
body: <p>I'm attempting to build local Ruby documentation as suggested here:</p>
  
  <p><a href="https://github.com/toy/doc" rel="nofollow">https://github.com/toy/doc</a></p>
  
  <p>However when I use the default Rakefile I get the following:</p>
  
  <pre><code>[Documentation]$ rake build
  configuring and updating: 100.0%
  rake aborted!
  undefined method `available?' for Gem:Module
  /Users/snowcrash/.rvm/gems/ruby-2.0.0-p195/gems/sdoc-0.2.20/lib/sdoc/json_backend.rb:9:in `&lt;top (required)&gt;'
  </code></pre>
  
  <p>Any suggestions?</p>