Add image "version" metadata in test_snapshot_pattern
Add image "version" metadata in test_snapshot_pattern

Add image "version" metadata to the snapshot image in
test_snapshot_pattern as shown in the related bug. Creating
another test just to update the metadata is not worth it.

Change-Id: I2f1093616dc7c4268a0bda5a4854da23423f4cab
Related-Bug: #1717547

openstack/tempest,cisco-openstack/tempest,openstack/tempest,cisco-openstack/tempest