[RFC] Deprecate the YamlFileLoader and the ArrayLoader

[stof]

Loading features from Yaml files is not something that is needed by Behat. And the format of those Yaml files (which is the array-based format of the ArrayLoader used internally by the YamlFileLoader) is not specified (nor documented) anyway.

AFAICT, this loader is mostly used by our testsuite, to load the reference files for comparison (which means it should probably never have been part of the package but only of the testsuite...).

I suggest deprecating those 2 classes.

Our tests fixtures used by ParserTest should first be migrated to the gherkin testdata format (which will also help for upstreaming them). This is tracked in #389.

[acoulton]

Thanks, I was going to ask about that as I wasn't sure of the history of ArrayLoader but it looked like it was indeed mostly a test class.

I'd agree with migrating the parser examples to NDJson and deprecating them, I can do that.