Enable SCiMMA kafka on minikube deployment

That would allow testing the functionality of kafka alert without using the four deployments at Caltech.

• add the optional entry auth to kafka_alert_config dictionary entry.
• The entry now may have: 'scimma': {'url': ... , 'suffix': .. , 'skymap_encoder': .. , 'auth': ..}
• In kafka boot step, the code does not change if this entry is not present.