Braintree

* Add error code constants
* Allow PayPal parameters to be sent in options.paypal

* Add risk_data to Transaction and Verification with Kount decision and id
* Add verification_amount an option when creating a credit card
* Add TravelCruise industry type to Transaction
* Add room_rate to Lodging industry type
* Add CreditCardverification as the latest verification on that credit card
* Add ApplePay support to all endpoints that may return ApplePayCard objects
* Align WebhookTesting with other client libraries

* Allow descriptor to be passed in Funding Details options params for Merchant Account create and update.

* Add additional_processor_response to transaction

* Allow payee_email to be passed in options params for Transaction create

* Added paypal specific fields to transaction calls
* Added SettlementPending, SettlementDeclined transaction statuses