Stop running grenade-py3
Stop running grenade-py3

It is not testing openstacksdk patches, so running it is a waste
of resources.

Change-Id: I8be6e0c10516224370bec452a87e8a27b5d8fa96

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