title: File rotation using winston works unexpected
body: <p>I have created a <a href="https://github.com/flatiron/winston" rel="nofollow">Winston</a> logger:</p>
  
  <pre><code>_logger.add(logger.transports.File, {
      filename: conf_fileName,
      timestamp:'true',
      maxsize: 1024,
      maxFiles: 2
  });
  </code></pre>
  
  <p>But after couple of hours I have lot of files in size of ~2kb. Is there something wrong with the logger definition?</p>