v7.8.0

• Removes the deprecated, unusable add_credit_card function
  • Stripe has disabled the ability to pass plain credit card details over the wire and now requires using Stripe.js/Elements/Checkout. Follow the Decentralized (EasyPost-Manage Billing) Guide for more details on the new flow to use.
  • Makes referral_customer.retrieve_easypost_stripe_api_key public to help facilitate adding credit cards using Stripe.js
• Adds support for FedexDefaultAccount, GofoWalletAccount, UpsDapAccount, UniUniWalletAccount, and VehoWalletAccount by properly routing carrier-account create requests to the /carrier_accounts/open endpoint.