Defalt val. of hpa.metrics to the correct type

This sets the hpa.metrics key to its correct default value. Which is an array and not a dict. Having it as a dict. gives issues as seen in #79. Which I hope to solve with this PR.

See: https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/horizontal-pod-autoscaler-v2/#HorizontalPodAutoscalerSpec for the official ref. docs on HPA and the `metrics` key type specifically.

Thank you.

Signed-off-by: Lars Bengtsson <[email protected]>
Signed-off-by: Lars Bengtsson <[email protected]>

Author: larssb

charts/coredns/values.yaml

@@ -240,7 +240,7 @@ hpa:
   enabled: false
   minReplicas: 1
   maxReplicas: 2
-  metrics: {}
+  metrics: []
 
 ## Configue a cluster-proportional-autoscaler for coredns
 # See https://github.com/kubernetes-incubator/cluster-proportional-autoscaler