Possibility to customize spray-json JsonProtocol

[lcor1979]

Hi,

I'm using slack-scala-bot-core 0.2.1 which depends on spray-json 1..3.1. No I've added a dependency to akka-http-spray-json 10.0.3 which depends on spray-json 1.3.3.

The problem is that there is an incompatibility in the API between spray-json 1.3.1 and 1.3.3 which causes an error :

java.lang.NoSuchMethodError: spray.json.StandardFormats$class.optionFormat(Lspray/json/StandardFormats;Lspray/json/JsonFormat;)Lspray/json/StandardFormats$OptionFormat;

https://github.com/spray/spray-json/issues/158

A possible fix would be to recompile slack-scala-bot-core with spray-json 1.3.3 but that means I have to embed this version in my project.

Is there a possibility to customize or replace the Unmarshallers object used in ApiActor ?

Thank you