Fix deployments (#5421)

docs/tutorials/stateless-application/guestbook/frontend-deployment.yaml

@@ -1,8 +1,12 @@
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1beta2
 kind: Deployment
 metadata:
   name: frontend
 spec:
+  selector:
+    matchLabels:
+      app: guestbook
+      tier: frontend
   replicas: 3
   template:
     metadata:

docs/tutorials/stateless-application/guestbook/redis-master-deployment.yaml

@@ -1,8 +1,13 @@
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1beta2
 kind: Deployment
 metadata:
   name: redis-master
 spec:
+  selector:
+    matchLabels:
+      app: redis
+      role: master
+      tier: backend
   replicas: 1
   template:
     metadata:

docs/tutorials/stateless-application/guestbook/redis-slave-deployment.yaml

@@ -1,8 +1,13 @@
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1beta2
 kind: Deployment
 metadata:
   name: redis-slave
 spec:
+  selector:
+    matchLabels:
+      app: redis
+      role: slave
+      tier: backend
   replicas: 2
   template:
     metadata: