Ocpp

- [167](https://github.com/mobilityhouse/ocpp/issues/167) Fix OCPP 2.0.1 call payloads for `RequestStartTransactionPayload` and `RequestStopTransactionPayload`.

- [114](https://github.com/mobilityhouse/ocpp/issues/114) Make casing of `ocpp.v16.enums`'s attributes consistent. Thanks [tropxy](https://github.com/tropxy)
- [147](https://github.com/mobilityhouse/ocpp/issues/147) Fix type hint for `ocpp.v16.call.ChangeAvailabilityPayload`. Thanks [laysauchoa](https://github.com/laysauchoa)
- [150](https://github.com/mobilityhouse/ocpp/issues/150) Log in to Docker hub to prevent being rate limited.
- [154](https://github.com/mobilityhouse/ocpp/issues/154) Speed up handling of `Call`s by caching `Draft4Validator` instances.

- [104](https://github.com/mobilityhouse/ocpp/issues/104) Allow `CallError`s to be catched. Thanks [tmh-azinhal](https://github.com/tmh-azinhal)
- [142](https://github.com/mobilityhouse/ocpp/issues/142)[#143](https://github.com/mobilityhouse/ocpp/issues/143) Add support for OCPP 2.0.1. Thanks [tropxy](https://github.com/tropxy)
- [137](https://github.com/mobilityhouse/ocpp/issues/137) Fix generation route map when using `property`. Thanks [fa1k3n](https://github.com/fa1k3n)

- [127](https://github.com/mobilityhouse/ocpp/issues/127) Fix type hints of enums.
- [130](https://github.com/mobilityhouse/ocpp/issues/130) Fix possible deadlock when using `after()` handlers.
- [131](https://github.com/mobilityhouse/ocpp/issues/131) Add CI support for Python 3.9. Thanks [laysauchoa](https://github.com/laysauchoa)!

- [117](https://github.com/mobilityhouse/ocpp/issues/117) Fix handling of async `after()` handlers.

- [95](https://github.com/mobilityhouse/ocpp/issues/95) Remove use of deprecated `asyncio.coroutine()`. Thanks [laysauchoa](https://github.com/laysauchoa)!
- [105](https://github.com/mobilityhouse/ocpp/issues/105) Implement `__str__()` for all exceptions. Thanks [laysauchoa](https://github.com/laysauchoa)!
- [110](https://github.com/mobilityhouse/ocpp/issues/110) Subclass OCPP 1.6 enums from `str` and `enum.Enum`.
- [113](https://github.com/mobilityhouse/ocpp/issues/113) Use OCPP 1.6 enums as type hints in calls and call results.