Include 'service_name' support in _parse_service_catalog_auth_v3 for Openstack Drivers

[steve-gregory]

The 'service_name' attribute was being left out when parsing the v3 ServiceCatalog returned by OpenStack. As a result, this error would occur: LibcloudError: <LibcloudError in None 'Could not find specified endpoint'>

The solution is to parse and add the service_name to the OpenStackServiceCatalogEntry similar to how it was done in _parse_service_catalog_auth_v2.

[jimbobhickville]

+1 makes sense to me

[tonybaloney]

Thanks @steve-gregory will merge

[Kami]

Thanks.

It's been a while since I wrote this, but IIRC, name was not available in the service catalog when I was originally testing this. It's possible that things have changed since then, but some tests would also be good :)