there is a bug in Kubernetes 1.6.1 that causes an error when validating the kubernetes environment and etcd. (https://github.com/kubernetes/kubernetes/pull/39716) I found that using the 1.7.0 version I did not get this error. Affects the README, this file and the client configuration (moving to 1.7.0 to match)
Unless the region is explicitly passed, I get the error:
```
ERROR: (gcloud.compute.target-pools.create) Some requests did not succeed:
- Invalid value for field 'region': 'us-central1-b'. Unknown region.
```
David Ross