- from stripe only to payment gateway abstract
- from reservation params style to unified cart_items
TODO: fix not passing tests,
subscriptions/renew_as_admin_test.rb fails because InvoiceItem(9).amount = nil
We prevent the currency from being changed if any stripe payment was made, because a stripe user cannot made pay with different currencies. If we try to charge a user with a different currency than the currency he used for a previous payment, this will fail; so we must prevent this case
