title: rbenv & ruby-build not showing the same list of version
body: <p>I'm trying to install the latest ruby version (ie. 2.1.1) with rbenv.</p>
  
  <p>After upgrading brew, ruby-build and rbenv the available ruby versions differs.</p>
  
  <p>Executing:</p>
  
  <pre><code>ruby-build --definitions
  </code></pre>
  
  <p>gives me (only versions above 2.0):</p>
  
  <pre><code>2.0.0-dev
  2.0.0-p0
  2.0.0-p195
  2.0.0-p247
  2.0.0-p353
  2.0.0-p451
  2.0.0-preview1
  2.0.0-preview2
  2.0.0-rc1
  2.0.0-rc2
  2.1.0
  2.1.0-dev
  2.1.0-preview1
  2.1.0-preview2
  2.1.0-rc1
  2.1.1
  2.2.0-dev
  </code></pre>
  
  <p>With RBenv:</p>
  
  <pre><code>rbenv install -l 
  </code></pre>
  
  <p>gives me (only versions above 2.0):</p>
  
  <pre><code>2.0.0-dev
  2.0.0-p0
  2.0.0-p195
  2.0.0-p247
  2.0.0-p353
  2.0.0-preview1
  2.0.0-preview2
  2.0.0-rc1
  2.0.0-rc2
  2.1.0-dev
  2.1.0-preview1
  2.1.0-preview2
  </code></pre>
  
  <p>What is happening here ?</p>