Update 1.8+ deployment to v0.3.0

This updates the 1.8+ deployment files to use v0.3.0 (the current latest release).

Author: rtripat

deploy/1.8+/metrics-server-deployment.yaml

@@ -29,7 +29,7 @@ spec:
  emptyDir: {}
  containers:
  - name: metrics-server
- image: gcr.io/google_containers/metrics-server-amd64:v0.2.1
+ image: k8s.gcr.io/metrics-server-amd64:v0.3.0
  imagePullPolicy: Always
  volumeMounts:
  - name: tmp-dir