Create basic installation & setup for prometheus & grafana

As a ONAP developer, I would like to create a basic setup for prometheus & grafana to be able to test and show the metrics exposed by policy components. This can be very beneficial for demos & integration testing.

The current docker compose in policy/docker can be used as a reference to achieve this work - https://github.com/onap/policy-docker/blob/master/csit/docker-compose-all.yml

Policy components are exposing system level metrics already - https://jira.onap.org/browse/POLICY-3538 

The end goal for this work will be to have all policy components up and running along with prometheus & grafana. And the end points are configured correctly. Metrics exposed by components can be seen in prometheus.