This will move prometheus to OSH-infra to be included as part of
the basic infrastructure deploy for openstack-helm. It includes
charts for Prometheus, Node Exporter, Kube-State-Metrics, and
Alertmanager. It provides a base for monitoring and alerting
for the underlying infrastructure
Partially Implements: blueprint osh-monitoring
Change-Id: Ie453373b54c5f1825339ce0566e4b5d0f74abc20