Success page after purchasing a free item gives 404 error page

[meagan13]

Describe the bug
After checking out with Stripe when purchasing free items the user is directed to a 404 error page. The cart also isn't cleared of purchases. The purchased resources DO appear in the user profile, though.

To Reproduce
Steps to reproduce the behavior:

1. Add free resource(s) to card
2. Purchase items using Stripe
3. 404 page appears

Expected behavior
Success page should appear, and cart should clear.

• I am willing to submit a pull request for this issue.