Tom Pollard authored Mar 21, 2019 and bst-marge-bot committed Mar 29, 2019

This adds the initial Artifact 'abstractions', taking existing
test methods into a dedicated Artifact class. The class is
accessed via an instance attribute of the generic Cli() fixture.
This is in preperation for AaaP, to ensure existing tests pass
whilst creating an entry point for further abstractions when
necessary.