Release v2.11.0

Summary:

• Added support for Python 3.10
• Added a few missing properties and methods to result objects:
  • Payment.amount_chargedback
  • Payment.has_chargebacks()
  • Payment.amount_captured
  • Payment.has_captures()
  • Organization.vat_regulation
• Added support for split payments: Payment.routing and Payment.has_split_payments().
• Add some tests for code that was previously not covered.
• Corrected an error in the example code, reported by @YannickSoepnel