* Updated google.golang.org/api/container/v1beta1
* Added support for private_cluster and master_ipv4_cidr
This is to implement #1174. See
https://groups.google.com/forum/#!topic/google-cloud-sdk-announce/GGW3SQSANIc
* Added simple test for private_cluster and master_ipv4_cidr
* Review replies
* Added some documentation for private_cluster
* vendor container/v1beta1
* revendor container/v1beta1
* add beta scaffolding for gke resources
* fix json unmarshal error
* fix issues with trying to convert interface instead of struct
* same fixes but for node pool
* move setid calls back