add .venv to gitignore
add .venv to gitignore

Change-Id: I36856a31f7a68280f9b787e5ab9ce5ac3aa0dc60

dtroyer/python-openstacksdk,dtroyer/os-client-config,stackforge/python-openstacksdk,redhat-openstack/os-client-config,openstack/os-client-config,openstack/python-openstacksdk,stackforge/python-openstacksdk,dtroyer/python-openstacksdk,openstack/python-openstacksdk,switch-ch/os-client-config