Add API Readiness Probe

Now server bring up is syncronous, and we pre populate caches, add a
readiness probe to prevent too many API errors during upgrade.  Its
still not seamless according to my testing, but a lot better!

Author: spjmurray

charts/region/templates/api/deployment.yaml

@@ -35,6 +35,12 @@ spec:
           containerPort: 6060
         resources:
           {{- .Values.server.resources | toYaml | nindent 10 }}
+        readinessProbe:
+          # This should be large enough to preheat caches.
+          initialDelaySeconds: 10
+          httpGet:
+            path: /.well-known/openid-protected-resource
+            port: 6080
         securityContext:
           readOnlyRootFilesystem: true
       serviceAccountName: {{ .Release.Name }}-server