It depends how you feel. Weigh out the pros & cons first. But mainly - that is YOUR graudation party, and don't feel obliged to invite anyone who is going to make you feel uncomfortable or uneasy at your own event celebrating you. If they could appreciate you then, then why all of a sudden would they apologize to start a clean slate right when you're about to go off to college? It doesn't make much sense in my eyes, if you really want to make an effort with their friendship & if their apology seemed sincere, then go ahead and invite them. If it won't be a pleasant experience for you, than don't. Don't let someone ruin your night. Good luck!