Add ipaddress and futures to lower-constraints
Add ipaddress and futures to lower-constraints

These were missing but that didn't get noticed before. Changing the
requirements in the next patch triggers the error.

Change-Id: I65605e14fc73e4eb223b7c31a98d4758ca280c9d

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