title: Mongoose - Remove all documents found using a promise
body: <p>Im trying to bulk delete comments as a document rather than a model as i want to later use the pre-hook remove method.</p>
  
  <p>The below command finds multiple documents that satisfy the query and attempts to delete each comment one by one. After all are removed the next() function is called if there is any error during the stage it should catch it.</p>
  
  <pre><code>Comment.find({'moment': this._id})
      .then(((comments) =&gt; Promise.each(comments, (comment) =&gt; comment.remove()))
      .then(next())
      .catch(next()));
  </code></pre>
  
  <p>However this gives me an error and not delete the comment</p>
  
  <blockquote>
    <p>"TypeError: (intermediate value).then is not a function"</p>
  </blockquote>