title: Getting "Error: failed to connect to tunnel VM" with intern/saucelabs
body: <p>I'm just starting out with intern/saucelabs. Whenever I try a remote test, I'm getting <code>Error: failed to connect to tunnel VM.</code> </p>
  
  <p>My intern.js has</p>
  
  <pre><code>environments: [
      { browserName: 'firefox', version: '28'},
  ],
  tunnel: 'SauceLabsTunnel',
  tunnelOptions: {
     username: 'foo',
     accessKey: 'xxxxxxxxxxxx-xxxx-xxxx-xxxx-xxxx'
  },
  </code></pre>
  
  <p>Execution log</p>
  
  <pre><code>$ intern-runner config=theintern/intern-sauce.js
  Listening on 0.0.0.0:9000
  Starting tunnel...
  Using no proxy for connecting to Sauce Labs REST API.
  **********************************************************
  A newer version of Sauce Connect (build 1283) is available!
  Download it here:
  https://saucelabs.com/downloads/sc-4.3-linux.tar.gz
  **********************************************************
  Started scproxy on port 44275.
  Starting secure remote tunnel VM...
  Secure remote tunnel VM provisioned.
  Tunnel ID: 6586b9012ca2424b8ecd6bd6970e996c
  Secure remote tunnel VM is now: booting
  Secure remote tunnel VM is now: running
  Remote tunnel host is: maki76026.miso.saucelabs.com
  Using no proxy for connecting to tunnel VM.
  Establishing secure TLS connection to tunnel...
  Cleaning up.
  Finished! Deleting tunnel.
  Error: failed to connect to tunnel VM.
  Error: failed to connect to tunnel VM.
    at reject  &lt;../../../../../../../usr/lib/node_modules/intern/node_modules/digdug/SauceLabsTunnel.js:353:17&gt;
    at readStartupMessage  &lt;../../../../../../../usr/lib/node_modules/intern/node_modules/digdug/SauceLabsTunnel.js:381:12&gt;
    at &lt;../../../../../../../usr/lib/node_modules/intern/node_modules/digdug/SauceLabsTunnel.js:434:12&gt;
    at Array.some  &lt;native&gt;
    at Socket.&lt;anonymous&gt;  &lt;../../../../../../../usr/lib/node_modules/intern/node_modules/digdug/SauceLabsTunnel.js:428:21&gt;
    at Socket.EventEmitter.emit  &lt;events.js:117:20&gt;
    at Socket.&lt;anonymous&gt;  &lt;_stream_readable.js:746:14&gt;
    at Socket.EventEmitter.emit  &lt;events.js:92:17&gt;
    at emitReadable_  &lt;_stream_readable.js:408:10&gt;
    at emitReadable  &lt;_stream_readable.js:404:5&gt;
  </code></pre>
  
  <p>In case it's significant, I'm currently on the free tier.</p>