* Allow groups of workers to be defined and joined to
a cluster (i.e. worker pools)
* Move worker resources into a Terraform submodule
* Output variables needed for passing to worker pools
* Add usage docs for AWS worker pools (advanced)
* Template terraform-render-bootkube's multi-line kubeconfig
output using the right indentation
* Add `kubeconfig` variable to google-cloud controllers and
workers Terraform submodules
* Remove `kubeconfig_*` variables from google-cloud controllers
and workers Terraform submodules
* Allow kube-dns to respond to DNS queries with a custom
suffix, instead of the default 'cluster.local'
* Useful when multiple clusters exist on the same local
network and wish to query services on one another
