Add a test for functions with keyword only arguments
Add a test for functions with keyword only arguments

This adds a test to ensure that no error is raised if a trailing comma
is missing from a function definition that has keyword only arguments.

Reviewed-by: Jakub Stasiak <1d3764b91b902f6b45836e2498da81fe35caf6d6@stasiak.at>

smarkets/flake8-strict