title: npm5 does not accept proxy settings
body: <p><strong>I upgraded to latest npm 5 today and it started throwing me following error.</strong> </p>
  
  <blockquote>
  <pre><code>npm ERR! code E407
  npm ERR! 407 Proxy Authorization Required: &lt;node-module&gt;
  </code></pre>
  </blockquote>
  
  <p>I have proxy setting configured in .npmrc file. Does NPM 5 maintain any other file for proxy setting?</p>