I have started collaborating with a few friends on a project & they use the heroku git repository.
I cloned the repository a few days ago and they have since mad
You can always do
git fetch && git merge --ff-only origin/master
and you will either get (a) no change if you have uncommitted changes that conflict with upstream changes or (b) the same effect as stash/pull/apply: a rebase to put you on the latest changes from HEAD and your uncommitted changes left as is.