title: TSD error: self signed certificate in certificate chain
body: <p>I am following the <a href="https://angular.io/docs/js/latest/quickstart.html" rel="noreferrer">Angular 2 quick start guide</a> and I'm stuck right at the beginning of it.</p>
  
  <p>My company is filtering our network connections and modifying SSL negociation. In a man in the middle style they assign a self signed certificate as the CA of the destination's certificate.</p>
  
  <p>Therefore when I execute the second command </p>
  
  <pre><code>npm install -g tsd
  tsd query angular2 --action install
  </code></pre>
  
  <p>I get this:</p>
  
  <pre><code>stream.js:75
        throw er; // Unhandled stream error in pipe.
              ^
  Error: self signed certificate in certificate chain
      at Error (native)
      at TLSSocket.&lt;anonymous&gt; (_tls_wrap.js:908:38)
      at emitNone (events.js:67:13)
      at TLSSocket.emit (events.js:163:7)
      at TLSSocket._finishInit (_tls_wrap.js:496:8)
  </code></pre>
  
  <p>Does anybody know a way of disabling the self signed certificate verification?</p>