Make test_molecule.py script reading scenario test_vars.yml
and react based on existing test_tags, molecule_tags_enforce,
test_skip_tags, and molecule_skip_tags_enforce variables of it:
* (skip_)tags configured, not enforced - molecule ignores it, leaving
it for the converge playbook control or not;
* (skip_)tags configured, and enforced - molecule applies it, even if
the converge playbook controls it as well (likely making it wrong);
This is required because converge may not always control skipping tags.
For example, include_tasks can only apply tags, but not skip it.
Also, molecule tags, if included, might conflict with tags management
of converge playbooks. So provided enfore-or-not it options help to
tweak that behavior case by case.
Change-Id: I0e3193c5f64457e55209891105df990c01dd2657
Signed-off-by: Bogdan Dobrelya <bdobreli@redhat.com>