Automatic merge from submit-queue

Add kubectl describe storageclass.

Sample output:

```
Name:		fast
Annotations:	storage.beta.kubernetes.io/default-class=true
Provisioner:	kubernetes.io/aws-ebs
Parameters:	type=gp2
No events.

Name:		slow
Annotations:	<none>
Provisioner:	kubernetes.io/aws-ebs
Parameters:	type=sc1
No events.
```
(it looks nicely aligned in terminal)

Proposing 1.4, it's bugfix, not a feature.