Implement support for storage class parameter - zone/zones/allowedTopologies

[leakingtapan]

zone/zones are needed for k8s version v1.10 and v1.11. These two fields are deprecated in v1.12 in favor of allowedTopologies.

[leakingtapan]

ref #31

[leakingtapan]

Tested allowedTopologies is supported once topology is enabled using VolumeScheduling.

sc used for testing:

kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: zone-sc
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: com.amazon.aws.csi.ebs
volumeBindingMode: WaitForFirstConsumer
allowedTopologies:
- matchLabelExpressions:
  - key: com.amazon.aws.csi.ebs/zone
    values:
    - us-east-1b

No driver change will be needed in v1.12+ for this feature. I will add documentation for this.