[examples.storage/minio] update deploy config version

examples/storage/minio/minio-distributed-statefulset.yaml

-apiVersion: apps/v1beta1
+apiVersion: apps/v1beta2
 kind: StatefulSet
 metadata:
   name: minio
 spec:
+  selector:
+    matchLabels:
+      app: minio
   serviceName: minio
   replicas: 4
   template:

examples/storage/minio/minio-standalone-deployment.yaml

-apiVersion: extensions/v1beta1
+apiVersion: apps/v1beta2
 kind: Deployment
 metadata:
   # This name uniquely identifies the Deployment
   name: minio-deployment
 spec:
+  selector:
+    matchLabels:
+      app: minio
   strategy:
     type: Recreate
   template: