unfortunate use of kwarg 'kwargs' results in some arguments not having effect

[imLew]

In a couple of places (e.g. rasa.train and rasa.core.train) we have a keyword argument called kwargs.
This is a confusing name as **kwargs is conventionally used to capture 0 or more additional, optional keyword arguments.
These function signatures should be changed, either by using a different name for this variable (additional_arguments) or by adapting them to use **kwargs.

This also causes the argument dump_stories of rasa.train to have no effect at all. (See https://forum.rasa.com/t/how-can-i-use-dump-stories-from-script/15433)

Update:
Another place where we use kwargs as a name for a dict instead of a container for optional keyword arguments is

rasa/rasa/test.py

Line 37 in bd83681

def test(

[AlvaroMonteagudo]

Any thoughts on this, it's been a while

[imLew]

I'm sorry @AlvaroMonteagudo, we haven't had time to address this yet.
Were you not able to fix it locally?