* Add explicit "providers" section to modules for Terraform v0.11.x
* Retain support for Terraform v0.10.4+
* Add migration guide from Terraform v0.10.x to v0.11.x for those managing
existing clusters (action required!)
* Change controllers ASG to heterogeneous EC2 instances
* Create DNS records for each controller's private IP for etcd
* Change etcd to run on-host, across controllers (etcd-member.service)
* Reduce time to bootstrap a cluster
* Deprecate self-hosted-etcd on the AWS platform
* Change controllers from a managed group to individual instances
* Create discrete DNS records to each controller's private IP for etcd
* Change etcd to run on-host, across controllers (etcd-member.service)
* Reduce time to bootstrap a cluster
* Deprecate self-hosted-etcd on the Google Cloud platform
* Remove performance note that the GCE vs AWS network performance
is not an equal comparison. On both platforms, workers now span the
(availability) zones of a region.
* Testing host-to-host and pod-to-pod network bandwidth between nodes
(now located in different zones) showed no reduction in bandwidth
* Run etcd peers with TLS across controller nodes
* Deprecate self-hosted-etcd on the Digital Ocean platform
* Distribute etcd TLS certificates as part of initial provisioning
* Check the status of etcd by running `systemctl status etcd-member`