title: gridfs-stream createWriteStream not uploading data
body: <p>I am using following code to create a file in mongodb. I get no error. But when i chech my <code>Test</code> database nothing is seen there uploaded. What am i doing wrong?</p>
  
  <pre><code>var GridStrm = require('gridfs-stream');
      console.log('Logo Upload');
  
      var conn = mongoose.createConnection('localhost', 'Test', 27017);
  
      var gfs = GridStrm(conn.db, mongoose.mongo);       
  
      var writeStream = gfs.createWriteStream('file.txt');
      fs.createReadStream('d:\\somepath').pipe(writestream);
  </code></pre>
  
  <p>I get the error <code>Error: EISDIR, read</code>.</p>
  
  <p>I got new error :-</p>
  
  <pre><code>events.js:72
          throw er; // Unhandled 'error' event
                ^
  Error: Cannot determine state of server
      at canCheckoutReader 
  </code></pre>
  
  <p>I further tried the following code :-</p>
  
  <pre><code>req.pipe(gfs.createWriteStream({
          filename: 'test'
      }));
      res.send("Success!");
  </code></pre>
  
  <p>But still no result.</p>