Pass hints to Cinder scheduler in create_volume
Pass hints to Cinder scheduler in create_volume

This commit adds support for passing 'scheduler_hints'
as kwarg in create_volume.

Change-Id: I85915fab03f2bff77a21802791f2f6a7579815f2

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