Merge pull request #1279 from scholzj/patch-1

Use apps/v1 for the deployment to be compatible with Kubernetes 1.16

docs/tutorials/digitalocean.md

@@ -25,11 +25,15 @@ Then apply one of the following manifests file to deploy ExternalDNS.
 
 ### Manifest (for clusters without RBAC enabled)
 ```yaml
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: external-dns
   strategy:
     type: Recreate
   template:
@@ -87,11 +91,15 @@ subjects:
   name: external-dns
   namespace: default
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: external-dns
   strategy:
     type: Recreate
   template:
@@ -118,11 +126,15 @@ spec:
 Create a service file called 'nginx.yaml' with the following contents:
 
 ```yaml
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: nginx
 spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: nginx
   template:
     metadata:
       labels: