Option to choose the carrier data format (XML vs. JSON vs. YAML) in all end user-facing converter tools

[vruusmann]

With the update to PMML schema version 4.4, it's time to shake things up some more!

In Scikit-Learn:

sklearn2pmml(pipeline, "MyPipeline.pmml.json", format = "json")

In R:

r2pmml(model, "MyModel.pmml.yaml", format = "yaml")

[vruusmann]

Related to the fact that the pmml-maven-plugin has been removed in the JPMML-Model 1.5.X development branch: jpmml/jpmml-model@f436d10

Such a plugin would be completely unnecessary, if people had the technical means to export the model in the desired data format right from the start.

[vruusmann]

One carrier data format could be "java", in which case the JPMML-Transpiler library is used to translate the PMML data structure into Java application code.

Related comment: jpmml/jpmml-model#23 (comment)