Adyen Python API Library v12.1.0

What's Changed

New Features 💎

• Checkout API;
  • In recurring_api.py add stored_payment_methods method
• Update all services by @AdyenAutomationBot in #299

Other Changes 🖇️

• Update base url readme by @DjoykeAbyah in #296
• Release v12.1.0 by @AdyenAutomationBot in #300

Full Changelog: v12.0.0...v12.1.0