title: Laravel update parent of parent updated_at timestamp
body: <p>I am trying to update a parent of a parents updated_at timestamp when the child model is updated. I can updated the parent model using the following code inside the child model</p>
  <pre><code>protected $touches = ['post']
  </code></pre>
  <p>but for example if I also wanted to update the user who made the posts updated_at timestamp how would I do this?</p>
  <p>I was hoping I could just add the following code to the Post.php model</p>
  <pre><code>protected $touches = ['user']
  </code></pre>
  <p>but this doesn't seem to work, the user model timestamp only gets updated if the Post record is updated.</p>