Enable stackdriver agents for GKE  by default. (#2118)
Enable stackdriver agents for GKE  by default. (#2118)

* We want to enable the stackdriver monitoring agents by default. This allows
  pod logs to be fetched by pod label which is very valuable.

* To enable this we need to use the v1beta1 API for GKE
https://cloud.google.com/kubernetes-engine/docs/reference/api-organization#beta

* Remove the field CLUSTER_VERSION from kfctl.sh
  This was added in #1888 but it doesn't look like it was actually being
  use to set the CLUSTER_VERSION; it looks like cluster-version is set
  in the deployment manager config cluster-kubeflow.yaml

Related to #1757
kubeflow/kubeflow,kubeflow/kubeflow,kubeflow/kubeflow,kubeflow/kubeflow,kubeflow/kubeflow,kubeflow/kubeflow