docs: use apps/v1 instead of extensions/v1beta1 in Deployment examples

The extensions/v1beta1 API is deprecated for Deployment and with 1.16 is
not served by default anymore. This breaks the examples on k8s 1.16.

See this blog post for details on the deprecations:

https://kubernetes.io/blog/2019/07/18/api-deprecations-in-1-16/

docs/faq.md

@@ -126,7 +126,7 @@ According to the `nginx-ingress-controller` [docs](https://github.com/kubernetes
 For example if your `nginx-ingress-controller` Service's name is `nginx-ingress-controller-svc` and it's in the `default` namespace the start of your resource YAML might look like the following. Note the second to last line.
 
 ```
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: nginx-ingress-controller

docs/tutorials/alibabacloud.md

@@ -96,13 +96,16 @@ 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:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -169,13 +172,16 @@ subjects:
   name: external-dns
   namespace: default
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -266,11 +272,14 @@ spec:
 
 ---
 
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: nginx
 spec:
+  selector:
+    matchLabels:
+      app: nginx
   template:
     metadata:
       labels:

docs/tutorials/aws-sd.md

@@ -65,13 +65,16 @@ Then apply the following manifest file to deploy ExternalDNS.
 ### Manifest (for clusters without RBAC enabled)
 
 ```yaml
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -128,13 +131,16 @@ subjects:
   name: external-dns
   namespace: default
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -177,11 +183,14 @@ spec:
 
 ---
 
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: nginx
 spec:
+  selector:
+    matchLabels:
+      app: nginx
   template:
     metadata:
       labels:

docs/tutorials/aws.md

@@ -70,13 +70,16 @@ For clusters with RBAC enabled, be sure to choose the correct `namespace`.
 
 ### Manifest (for clusters without RBAC enabled)
 ```yaml
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -135,13 +138,16 @@ subjects:
   name: external-dns
   namespace: default
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -229,11 +235,14 @@ spec:
 
 ---
 
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: nginx
 spec:
+  selector:
+    matchLabels:
+      app: nginx
   template:
     metadata:
       labels:

docs/tutorials/azure.md

@@ -174,13 +174,16 @@ 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:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -243,13 +246,16 @@ subjects:
   name: external-dns
   namespace: default
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -313,13 +319,16 @@ subjects:
 - kind: ServiceAccount
   name: external-dns
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -356,11 +365,14 @@ $ kubectl create -f externaldns.yaml
 Create a service file called 'nginx.yaml' with the following contents:
 
 ```yaml
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: nginx
 spec:
+  selector:
+    matchLabels:
+      app: nginx
   template:
     metadata:
       labels:

docs/tutorials/cloudflare.md

@@ -31,13 +31,16 @@ 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:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -97,13 +100,16 @@ subjects:
   name: external-dns
   namespace: default
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -130,11 +136,14 @@ 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:
+  selector:
+    matchLabels:
+      app: nginx
   template:
     metadata:
       labels:

docs/tutorials/contour.md

@@ -4,13 +4,16 @@ It is meant to supplement the other provider-specific setup tutorials.
 
 ### Manifest (for clusters without RBAC enabled)
 ```yaml
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -73,13 +76,16 @@ subjects:
   name: external-dns
   namespace: default
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:

docs/tutorials/designate.md

@@ -40,13 +40,16 @@ It is important to manually create all the zones that are going to be used for k
 Create a deployment file called `externaldns.yaml` with the following contents:
 
 ```yaml
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: external-dns
 spec:
   strategy:
     type: Recreate
+  selector:
+    matchLabels:
+      app: external-dns
   template:
     metadata:
       labels:
@@ -85,11 +88,14 @@ $ kubectl create -f externaldns.yaml
 Create a service file called 'nginx.yaml' with the following contents:
 
 ```yaml
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: nginx
 spec:
+  selector:
+    matchLabels:
+      app: nginx
   template:
     metadata:
       labels: