[webpayments] Minimum necessary information for merchant to process payment (#27)

To accept a payment method, a merchant must know how to process the response from the Payment Request API. Should there be a base universal response format? If so, some payment instruments may need more information in the returned message to figure out if the payment was successful, how is this other information placed in there?

This is related to issue #25, Payment Method Identifier Registry.

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/webpayments/issues/27