title: Cannot app.use(multer). "requires middleware function" error
body: <p>I'm just starting learning NodeJS and I am stuck with a problem. I would like to upload files to my server. To do so I searched and found out this module <a href="https://github.com/expressjs/multer">multer</a>. Doing as the example on GitHub works:</p>
  
  <pre><code>var express = require('express');
  var multer = require('multer');
  var upload = multer({ dest: 'uploads/' });
  
  var app = express()
  
  app.post('/uploadImage', upload.single('image'), function(req, res) {
      console.log(req.file);
  });
  </code></pre>
  
  <p>On posting an image with FormData to <code>/uploadImage</code> the image is saved in the <code>uploads/</code> directory. The thing is the image is saved with a strange name and I would like to save it with its original name. 
  To do so I understood that I would have to call <code>app.use(multer({ dest: 'uploads/' }))'</code>  and then I would be able to access <code>req.file</code> in my function like: </p>
  
  <pre><code>app.post('/uploadImage', function(req, res) {
      console.log(req.file);
  });
  </code></pre>
  
  <p>But I get an error on trying app.use():</p>
  
  <pre><code>TypeError: app.use() requires middleware functions
      at EventEmitter.use (project\node_modules\express\lib\application
  .js:209:11)
  </code></pre>
  
  <p>Im using NodeJS 0.12.7 and Express 4.13.1</p>
  
  <p>How can I achieve that upload? Thanks. </p>