title: Automatically grading submissions in private git repositories
body: <p>We have an automatic homework grading script that work as follows:</p>
  <ul>
  <li>The students upload their solutions to their GitHub repositories, and submit URLs to their repositories.</li>
  <li>Our script reads the URLs, automatically clones each repository, and runs the tests on the files.</li>
  </ul>
  <p>It works well when the students' repositories are public, but now we would like to allow the students to submit private repositories too. What should the students do in order to allow our grading script to read their private repositories?</p>
  <p>One option is that we open a GitHub account for the script, and have the students add this account as &quot;collaborator&quot; to the repository they submit. But, this would require us to approve each such addition, which might take a long time (there are almost 300 students).</p>
  <p>Is there another, automated way to do this?</p>