title: VSTS rejected pull request completion workflow
body: <p>We have VSTS pull requests (PR's) set up to require 2 reviewers before the request can complete.</p>
  
  <p>This scenario happened today:</p>
  
  <ol>
  <li>Pull request created with 2 reviewers</li>
  <li>One reviewer accepted the PR and the other reviewer rejected</li>
  <li>The author fixed and pushed up the code</li>
  <li>The reviewer who had rejected the code approved</li>
  <li>The PR completed successfully without the first approver seeing the update</li>
  </ol>
  
  <p>We need the original approvals and rejections to be reset when the updated code comes in. Is this possible out of the box?</p>