v8.0.0

• #1283 Major version release of v8.0.0. The migration guide contains more information.
  (⚠️ = breaking changes):
  • ⚠️ Replace the legacy Order API with the new Order API.
    • Resource modified: Order.
    • New methods: cancel, list_line_items, reopen, and submit
    • Removed methods: pay and return_order
    • Removed resources: OrderItem and OrderReturn
    • Removed references from other resources: Charge.order
  • ⚠️ Rename \FinancialConnections\Account.refresh method to \FinancialConnections\Account.refresh_account
  • Add support for amount_discount, amount_tax, and product on LineItem

See the changelog for more details.