Add example script for HEAD requests
Add example script for HEAD requests

Change-Id: I3d2421f1fb6e0db02e01789edc78ca432e34975f

mtougeron/python-openstacksdk,briancurtin/python-openstacksdk,stackforge/python-openstacksdk,briancurtin/python-openstacksdk,openstack/python-openstacksdk,dtroyer/python-openstacksdk,dudymas/python-openstacksdk,openstack/python-openstacksdk,stackforge/python-openstacksdk,dudymas/python-openstacksdk,dtroyer/python-openstacksdk,mtougeron/python-openstacksdk