Ocpp

- [76](https://github.com/mobilityhouse/ocpp/issues/76) Fix names of 2 OCPP OCPP 2.0 call payloads.

- Add links to source and documentation in Pypi. [adamchainz](https://github.com/adamchainz)

- [71](https://github.com/mobilityhouse/ocpp/issues/71) Add unit Hertz. [bengarrett1971](https://github.com/bengarrett1971)

- [68](https://github.com/mobilityhouse/ocpp/issues/68) Fix validation of SetChargingProfile

- [63](https://github.com/mobilityhouse/ocpp/issues/63) Remove spaces after separators before sending message
- [65](https://github.com/mobilityhouse/ocpp/issues/65) `ocpp.ChargePoint.call()` doesn't validate the messages

- [57](https://github.com/mobilityhouse/ocpp/issues/57) Implement errata v4 for OCPP 1.6. Thanks [darander](https://github.com/darander)