title: ERROR: Failed to build gem native extension - Error installing mysql2
body: <p>error while running bundle install</p>
  
  <pre><code>Installing mysql2 (0.3.11) with native extensions 
  Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
  ...
  Make sure that `gem install mysql2 -v '0.3.11'` succeeds before bundling.
  </code></pre>
  
  <p>when i run Make sure that <code>gem install mysql2 -v '0.3.11'</code>.I still get the same error.</p>