New deployments endpoint (#2986)

* Update deployments for 1.6

* Update all deployments in docs to use the new endpoint

docs/user-guide/walkthrough/deployment-update.yaml

@@ -1,4 +1,4 @@
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1beta1
 kind: Deployment
 metadata:
   name: nginx-deployment
@@ -13,4 +13,4 @@ spec:
       - name: nginx
         image: nginx:1.8 # Update the version of nginx from 1.7.9 to 1.8
         ports:
-        - containerPort: 80
+        - containerPort: 80