* `asset_dir` is an absolute path to a directory where generated
assets from terraform-render-bootstrap are written (sensitive)
* Change `asset_dir` to default to "" so no assets are written
(favor Terraform output mechanisms). Previously, asset_dir was
required so all users set some path. To take advantage of the
new optionality, remove asset_dir or set it to ""
* Enable TLS for experimental self-hosted etcd
* Update the flannel Daemonset based on upstream
* Switch control plane components to run as non-root
* Add UpdateStrategy to control plane components
