Ocpp-van

- [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)

- [54](https://github.com/mobilityhouse/ocpp/issues/54) Add option to `on()` to skip schema validation

- [43](https://github.com/mobilityhouse/ocpp/issues/43) Fix validation of 3 OCPP v1.6 payloads containing floats

- [50](https://github.com/mobilityhouse/ocpp/issues/50) Fix RuntimeError when using ocpp.charge_point.ChargePoint.call

- [46](https://github.com/mobilityhouse/ocpp/issues/46) Fix potential deadlock
- [48](https://github.com/mobilityhouse/ocpp/issues/48) Make ocpp.v16.call.ReserveNowPayload.parent_id_tag optional