fixup storage examples

examples/experimental/persistent-volume-provisioning/README.md

@@ -51,7 +51,7 @@ The name of a StorageClass object is significant, and is how users can request a
 
 ```yaml
 kind: StorageClass
-apiVersion: extensions/v1beta1
+apiVersion: storage.k8s.io/v1beta1
 metadata:
   name: slow
 provisioner: kubernetes.io/aws-ebs
@@ -71,7 +71,7 @@ parameters:
 
 ```yaml
 kind: StorageClass
-apiVersion: extensions/v1beta1
+apiVersion: storage.k8s.io/v1beta1
 metadata:
   name: slow
 provisioner: kubernetes.io/gce-pd
@@ -86,7 +86,7 @@ parameters:
 #### GLUSTERFS
 
 ```yaml
-apiVersion: extensions/v1beta1
+apiVersion: storage.k8s.io/v1beta1
 kind: StorageClass
 metadata:
   name: slow
@@ -109,7 +109,7 @@ parameters:
 
 ```yaml
 kind: StorageClass
-apiVersion: extensions/v1beta1
+apiVersion: storage.k8s.io/v1beta1
 metadata:
   name: gold
 provisioner: kubernetes.io/cinder

examples/experimental/persistent-volume-provisioning/aws-ebs.yaml

 kind: StorageClass
-apiVersion: extensions/v1beta1
+apiVersion: storage.k8s.io/v1beta1
 metadata:
   name: slow
 provisioner: kubernetes.io/aws-ebs

examples/experimental/persistent-volume-provisioning/gce-pd.yaml

 kind: StorageClass
-apiVersion: extensions/v1beta1
+apiVersion: storage.k8s.io/v1beta1
 metadata:
   name: slow
 provisioner: kubernetes.io/gce-pd

examples/experimental/persistent-volume-provisioning/glusterfs-dp.yaml

-apiVersion: extensions/v1beta1
+apiVersion: storage.k8s.io/v1beta1
 kind: StorageClass
 metadata:
   name: slow