title: Permission denied for git dependencies in package.json
body: <p>I try setup git dependencies in package.json:</p>
  
  <pre><code>"dependencies": {
      "myLib": "git+ssh://git@domain.com:user/myLib.git"
    }
  </code></pre>
  
  <p>When I do <code>sudo npm install</code> I got errors:</p>
  
  <pre><code>Warning: Permanently added the RSA host key for IP address 'myIp' to the list of known hosts.
  
   Permission denied (publickey).
  </code></pre>
  
  <p>Allthough I can clone successfully the same lib to that machine:</p>
  
  <pre><code>git clone git@domain.com:user/myLib.git
  </code></pre>
  
  <p>So I have valid ssh keys.</p>
  
  <p>My OS is <strong>OSX</strong> but I have the same problem on <strong>Linux</strong>.</p>