Fix coverage running
Fix coverage running

The post coverage job fails, fix invocation - this is not shade but
openstacksdk.

Prior to this change, running tox -e cover resulted in:
...
Coverage.py warning: Module shade was never imported.
(module-not-imported)
Coverage.py warning: No data was collected. (no-data-collected)

Change-Id: I920fee18083d41d0938bbe19b4b7cf7759aece0c

openstack/python-openstacksdk,stackforge/python-openstacksdk,openstack/python-openstacksdk,stackforge/python-openstacksdk,dtroyer/python-openstacksdk,dtroyer/python-openstacksdk