title: (node:2157) DeprecationWarning: Mongoose: mpromise (mongoose's default promise library) is deprecated, plug in your own promise library instead
body: <p>I'm using MEAN stack and every time I save an user i get this warning</p>
  
  <p>(node:2157) DeprecationWarning: Mongoose: mpromise (mongoose's default promise library) is deprecated, plug in your own promise library instead: <a href="http://mongoosejs.com/docs/promises.html" rel="nofollow noreferrer">http://mongoosejs.com/docs/promises.html</a></p>
  
  <p>this is where I save user data</p>
  
  <pre><code>user.save(function(err, user) {
      if (err) return res.status(500).send({message: There was an error creating user. Please try again later: ${err}})
      return res
        .status(200)
        .send({ message: 'user successfully created' });
    });
  </code></pre>
  
  <p>what should I do to delete warning in console?</p>