title: rbenv Your Ruby version is 2.0.0, but your Gemfile specified 2.1.2 but the only version installed is 2.1.2
body: <p>I'm using <code>rbenv</code> but I can run my server with: <code>rails s</code>
  display me an error with:</p>
  
  <blockquote>
    <p>Your Ruby version is 2.0.0, but your Gemfile specified 2.1.2</p>
  </blockquote>
  
  <p>I tried uninstall the version <code>2.0.0</code> but this version doesn't exist
  <code>rbenv unistall 2.0.0</code></p>
  
  <p>And I tried with:
  <code>rvm implode
  -bash: rvm: command not found</code>
  because I'm not using <code>rvm</code>, what I can do to run my server?</p>
  
  <p>And my ruby  build says:</p>
  
  <pre><code>$ ruby-build --version
  ruby-build 20141113
  </code></pre>