title: Unable to find RubyGems in site_ruby or core Ruby？
body: <p>I want to install ruby on my windows,</p>
  
  <pre><code>  ruby dk.rb init
  </code></pre>
  
  <p>then modify config.yml, and install:</p>
  
  <pre><code>E:\devkit&gt;ruby dk.rb install
  </code></pre>
  
  <p>but the output is error:</p>
  
  <pre><code>[ERROR] Unable to find RubyGems in site_ruby or core Ruby. Please
  install RubyGems and rerun 'ruby dk.rb install'.
  </code></pre>
  
  <p>Did I lose something?</p>