lack of OCPP 2.0.1 version

[SzestKam]

Hello,

Could you add ocpp_2.0.1 for ocpp-transport/src/main/kotlin/com/izivia/ocpp/transport/OcppVersion.kt and also create RealChargePointOperations201 apiFactory.

In the description of your lib, there is information you support this protocol version.

[edwardmp]

I might be mistaken, but I think (even though it's confusing) the current OCPP 2.0 support already covers this.

@lilgallon perhaps you can chip in since the README does say 2.0.1 is supported

[edwardmp]

Actually checked this against a 2.0.1 simulator, and it doesn't work properly.

The simulator (correctly) specifies the subprotocol ocpp2.0.1, yet this toolkit only supports ocpp2.0, which seems odd given 2.0 never matured beyond a draft.

This code should probably just be changed to use 2.0.1:
OCPP_1_5("ocpp1.5"), OCPP_1_6("ocpp1.6"), OCPP_2_0("ocpp2.0")