title: connect-busboy on('file') event not firing
body: <p>I'm having issues with uploading files. I have the following code:</p>
  
  <p><strong>App.js</strong></p>
  
  <pre><code>var bodyParser = require('body-parser');
  var busboy = require('connect-busboy');
  
  app.use(bodyParser.urlencoded({extended: false}));
  app.use(bodyParser.json());
  app.use(busboy({immediate: true, limits: {fileSize: 25 * 1024 * 1024}}));
  </code></pre>
  
  <p><strong>Attachments.js</strong></p>
  
  <pre><code>router.post('/:table/:id', function (req, res) {
      req.busboy.on('file', function (fieldname, file, filename, encoding, mimetype) {
          //Do stuff..
      });
  });
  </code></pre>
  
  <p>The 'file' event is not firing. I tried logging, it does get into the route, so I don't think it's a routing issue. Any thoughts, what am I doing wrong?</p>
  
  <p>Running versions: </p>
  
  <ul>
  <li>Express : <strong>v4.x</strong></li>
  <li>Body-Parser : <strong>v1.11.0</strong></li>
  <li>connect-busboy : <strong>v0.0.2</strong></li>
  </ul>