Add acceptance test for accessing prometheus/grafana

[pauldougan]

What

We say you can access prometheus and grafana via port-forwarding, but we do not currently have any tests that prove this is the case

Why

So we know we haven't broken the ability to access prometheus / grafana dashboards

If we don't do this

We will break access to the dashboard when we do deployments

It's done when

• We have a test in the deployer to prove that prometheus is up and can be accessed as expected
• We have a test in the deployer that proves the grafana is up and can be access as expected