title: Unable to write keys.dev.pub to: /home/ubuntu/.composer
body: <p>I'm following the instructions to install composer (<a href="https://getcomposer.org/download/](https://getcomposer.org/download/" rel="noreferrer">found here</a>). I just ran the line <code>php composer-setup.php</code> and the terminal returned:</p>
  
  <pre><code>All settings correct for using Composer
  Unable to write keys.dev.pub to: /home/ubuntu/.composer
  </code></pre>
  
  <p>I'm installing into a Ubuntu VM in Vagrant.</p>