Install Prometheus as part of bazel run everything.create.

[josephburnett]

We should install Prometheus in the cluster to act as a target for metrics and logging (#20). In particular, I want to get QPS metrics out of Prometheus for the purpose of faster autoscaling.

I did this manually and it worked fine. Except that all the istio_* metrics were missing. We will be replacing Nginx with Envoy (#112) so that might help in getting those metrics.

[mdemirhan]

#189 adds a system wide Prometheus instance and collects k8s, node and istio metrics.