Test CreditCards for PostFinance FlexCheckout

This plugin inserts additional buttons into the flexcheckout mask of PostFinance to provide test credit cards.
Depending on the brand, a valid card, an invalid card and a card with 3D secure is provided.

V1.2.0.0 Support for expiry date with textboxes
V1.3.0.1 Support for credit cards with 3ds V2.1