Make eventrouter compatible with k8s >= 1.16 (#18632)

In kubernetes 1.16 `apiVersion: apps/v1beta1` is retired now.

Snip from k8s CHANGELOG:
> Continued deprecation of extensions/v1beta1, apps/v1beta1,
> and apps/v1beta2 APIs; these extensions will be retired in 1.16!

Full changelog:
https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.16.md

Signed-off-by: Marco Kilchhofer <marco@kilchhofer.info>

stable/eventrouter/Chart.yaml

@@ -1,7 +1,7 @@
 apiVersion: v1
 description: A Helm chart for eventruter (https://github.com/heptiolabs/eventrouter)
 name: eventrouter
-version: 0.2.2
+version: 0.2.3
 appVersion: 0.2
 home: https://github.com/heptiolabs/eventrouter
 sources:

stable/eventrouter/templates/deployment.yaml

@@ -1,4 +1,8 @@
+{{- if semverCompare "^1.9-0" .Capabilities.KubeVersion.GitVersion }}
+apiVersion: apps/v1
+{{- else }}
 apiVersion: apps/v1beta1
+{{- end }}
 kind: Deployment
 metadata:
   labels: {{ include "eventrouter.labels" . | indent 4 }}