Azure: Allow to not provide tests to be ignored
As for now, a list of tests which will be ignored by Pytest is
mandatory. But actually, a list of tests to run is explicitly set
in yaml config. And thus, 'ignore' list should be an optional field.
This simplifies tests definitions to drop extra stuff.
Fixes: https://pagure.io/freeipa/issue/8202
Signed-off-by: Stanislav Levin <slev@altlinux.org>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>