• Fix a bug where class-based callables used as Django views (without using
  Django's regular class-based views) would not have csrf_exempt applied.
• New integration for Google Cloud Functions.
• Fix a bug where a recently released version of urllib3 would cause the SDK
  to enter an infinite loop on networking and SSL errors.
• Breaking change: Remove the traceparent_v2 option. The option has been
  ignored since 0.16.3, just remove it from your code.