I think your branch and commit is based on an older version of the main repo -- before some of your class mates added their links. I don't want to accept your commit and kill theirs.

Can you please try this
https://help.github.com/articles/fork-a-repo#pull-in-upstream-changes
 to pull these recent changes into your fork?

Then your pull request might update automatically. I don't know if this is possible through the browser.

If that seems too hard, just fork the current repo, edit your line, and make a new request.

Thanks for helping me learn how to deal with this situation.