Make create_image use **kwargs

As we discussed on
http://lists.openstack.org/pipermail/openstack-dev/2015-July/068864.html
All http POST/PUT methods need to contain **kwargs as their arguments.
This patch makes create_image use **kwargs.

NOTE: We cannot make update_image use **kwargs because the API requires
a list body, not dict body.

Partially implements blueprint consistent-service-method-names

Change-Id: Ic525e341712149699644ba39cafa5f91a700737f
4 files changed