title: Changing commit message in GitHub pull request
body: <p>I have pushed some code for review and have been asked to change couple of my commit messages.</p>
  <p>I tried doing <code>git rebase -i HEAD~5</code> since it isn't my latest commit which needs to be changed.</p>
  <p>Upon making changes, I now see that my branch has been diverged.
  What would have been the correct approach here?</p>
  <p>I am not that confident, so would probably end up creating a new pull request all together. But, I would have liked to change in same pull request so that review comment history would have been retained.</p>