Merge remote-tracking branch 'upstream/master'

Makefile

assets/prometheus/rules/node.rules

docs/developing-alerts-and-dashboards.md

hack/cluster-monitoring/deploy

hack/cluster-monitoring/teardown

manifests/grafana/grafana-deployment.yaml

manifests/prometheus-operator/prometheus-operator.yaml

manifests/prometheus/prometheus-cluster-role-binding.yaml

manifests/prometheus/prometheus-k8s-role-bindings.yaml

manifests/prometheus/prometheus-k8s-roles.yaml

manifests/prometheus/prometheus-k8s-rules.yaml

...ts/prometheus/prometheus-k8s-service-monitor-kubelet.yaml