Stripe doesn't allow for payments less than $0.50 and we don't handle it properly

Sometimes we have requests where the fee is something like $0.15 and someone tries to pay for it, but Stripe only allows for transactions of $0.50 or more. 

Sentry Error:
https://muckrock.sentry.io/issues/7090825026/?project=1422309&query=is%3Aunresolved&referrer=issue-stream

We should handle this gracefully. 

This could probably be roped into other work on small payments #343 