Update gitkube-setup.yaml to new k8s api

I've updated deployment apiVersion to apps/v1 due to 1.16 k8s api updates.
New api version also need selector field.

manifests/gitkube-setup.yaml

@@ -38,14 +38,17 @@ metadata:
   name: gitkube-ci-conf
   namespace: kube-system
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   labels:
     app: gitkubed
   name: gitkubed
   namespace: kube-system
 spec:
+  selector:
+    matchLabels:
+      app: gitkubed
   replicas: 1
   strategy:
     rollingUpdate:
@@ -101,14 +104,17 @@ spec:
           name: gitkube-ci-conf
         name: gitkube-ci-conf
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   labels:
     app: gitkube-controller
   name: gitkube-controller
   namespace: kube-system
 spec:
+  selector:
+    matchLabels:
+      app: gitkube-controller
   replicas: 1
   strategy:
     rollingUpdate:
@@ -134,5 +140,3 @@ spec:
           valueFrom:
             fieldRef:
               fieldPath: metadata.namespace
-
-