Rename mathods of v1 image_members_client

v2 image_members_client contains create_image_member() and
delete_image_member() and these method names are based
http://specs.openstack.org/openstack/qa-specs/specs/tempest/consistent-service-method-names.html

This patch renames v1's one also for the same methods.

Partially implements blueprint consistent-service-method-names

Change-Id: I547be28c45d69fa0628bb2c7278a3d1f6912c674
3 files changed