Log Message:
py-braintree: updated to 3.56.0

3.56.0:
Add PayPalHere details
Add networkResponseCode and networkResponseText to transactions and verifications
Add cavv, xid, ds_transaction_id, eci_flag, and three_d_secure_version, to \ 
three_d_secure_info
Add three_d_secure_info to credit_card_verification
Add GraphQLClient to BraintreeGateway class