This patch adds jsonschema validation for below Backups API's
* POST /v3/{project_id}/backups
* PUT /v3/{project_id}/backups/{backup_id}
* POST /v3/{project_id}/backups/{backup_id}/restore
* POST /v3/{project_id}/backups/{backup_id}/import_record
Made changes to unit tests to pass body as keyword argument as wsgi
calls action method [1] and passes body as keyword argument.
[1] https://github.com/openstack/cinder/blob/master/cinder/api/openstack/wsgi.py#L997
Change-Id: Idd6c6be1c8bdf4dcf730f67e75a58a0329fe5259
Partial-Implements: bp json-schema-validation