feat(pod): roll deployment for TLS certificates

The patch add the annotation `checksum/secret-<name of the TLS secret>` with the
sha512 value of the secret. This ensures a rolling update if the TLS secrets has
been updated. Such an update can be triggered by the cert-manager.

unittests/deployment/certificate.yaml

@@ -46,6 +46,9 @@ tests:
     certificate.new.issuerRef.kind: ClusterIssuer
     certificate.new.issuerRef.name: MyIssuer
   asserts:
+    - exists:
+        path: spec.template.metadata.annotations["checksum/secret-athens-proxy-unittest-tls"]
+      template: templates/deployment.yaml
     - contains:
         path: spec.template.spec.containers[0].env
         content: