title: Clean up pull request commits
body: <ul>
  <li>I branched off (<code>my_branch</code>) from <code>master</code>.</li>
  <li>While working on <code>my_branch</code>, there were updates to <code>master</code>.</li>
  <li>I was regularly re-basing <code>my_branch</code> to then latest <code>master</code>.</li>
  <li>With one re-base later though there was a conflict. I remember resolving the conflict and <code>git rebase --continue</code>. </li>
  <li>For some reason, rebase steps I took didn't help, I ended up performing a merge of the new commits to <code>master</code>.</li>
  <li>Between my last successful rebase and the current merge, there were a few commits in the master. These commits now merged onto <code>my_branch</code></li>
  <li>Now my pull request shows the changes from these commits that were merged.</li>
  </ul>
  
  <p>Is there a way for me to clean up the pull request to show only the changes I made?</p>
  
  <p>Also, is there a way for me to see in local what a pull request would look like for the reviewer? Is it just doing a diff between (1) the commit in <code>master</code> from where <code>my_branch</code> was created, and (2) the latest code I have in <code>my_branch</code>?</p>