cinder backup-delete should have a support for cinder backup force delete

[Itzik Brown]

According to https://review.openstack.org/#/c/166127/ Forcing a deletion of a backup should be supported.
Currently there is no such support in the client ( or at least there is no indication for this support in the help option).

Version
======
1.6.0

[Sheel Rana (ranasheel2000)]

Support for force-delete backups is already provided in cinder in below patchset
https://review.openstack.org/#/c/166127/

So, moved this from cinder to cinderclient.

Will provide patch for cinderclient support for force-delete backup..

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/313550

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/313550
Committed: https://git.openstack.org/cgit/openstack/python-cinderclient/commit/?id=11010ec9eb1de02a8c2dbea1257eca72e66829e2
Submitter: Jenkins
Branch: master

commit 11010ec9eb1de02a8c2dbea1257eca72e66829e2
Author: Sheel Rana <email address hidden>
Date: Fri May 6 19:01:46 2016 +0530

    Support for cinder backup force delete

    Cinder backup force delete is supported from cinder server
    side but cinderclient support is not present.

    This patchset adds support for cinder backup force delete
    from cinderclient side.

    Closes-Bug:#1567243

    Partially-Implements: blueprint snapshot-backup-force-delete

    Change-Id: I4ec38376d57ef6f74fefdd3bd2fea7a10bc51672

[Thierry Carrez (ttx)]

This issue was fixed in the openstack/python-cinderclient 1.8.0 release.