title: ruby-build: definition not found: 2.2.1
body: <p>I want to install new version of ruby by <code>rbenv install 2.2.1</code>, but I get the error </p>
  
  <pre><code>ruby-build: definition not found: 2.2.1
   The following versions contain 2.2.1 in the name:
    rbx-2.2.1
    rbx-2.2.10
  </code></pre>
  
  <p>Could you please let me know how should I install version 2.2.1?</p>
  
  <p>Thanks in advance!</p>