Merge branch 'deployment_api_version' of kosmos/gitea.kosmos.org into master

It was previously set to extensions/v1beta1. I have discovered that when
the Deployment is created as a extensions/v1beta1, it causes the
existing pod to be killed immediately when doing a rolling update. When
the Deployment was created as apps/v1, a rolling update behaves as
expected: a new pod is created, and the old one is only terminated once
the new pod is ready to serve traffic.

The existing Deployment resource will need to be deleted and recreated:

    kubectl delete deployment gitea-server
    kubectl apply -f gitea-server.yaml

Applying the file without deleting it first will not fix the issue with
rolling updates. It will cause a short downtime

kubernetes/gitea-server.yaml

@@ -1,4 +1,4 @@
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: gitea-server
@@ -6,6 +6,9 @@ metadata:
     app: gitea
 spec:
   replicas: 1
+  selector:
+    matchLabels:
+      app: gitea
   template:
     metadata:
       labels: