title: Renaming files using multer
body: <p>I have configured multer as;</p>
  
  <pre><code>var storage = multer.diskStorage({
    destination: function(req, file, cb) {
      cb(null,  '../images/profile');
    },
    filename: function(req, file, cb) {
      cb(null, req.body.username + '.jpeg');  // file does not get renamed
    }
  });
  
  var upload = multer({storage: storage});
  
  // Route that uses multer
  router.post('/auth/signup/upload', upload.single('image'), function(req, res) {
    console.log(req.body.username); // contains value
    res.send(); 
  });
  </code></pre>
  
  <p>Although req.body.username has a value, the file does not get renamed. 
  Wht am i missing here ?</p>