DEVOPS-4320 | Migrate cloud-config IMDSv1 requests to IMDSv2

Merge pull request unifio#22 from kjonick1/master

Add root_vol_size for openvpn server

v1.0.3

`docker-openvpn-server/cluster`: Optional output for EIP
  - worked through https://www.terraform.io/upgrade-guides/0-11.html#referencing-attributes-from-resources-with-count-0
to get eip alloc id output

v1.0.2

* Bump referenced cluster module in /certs: 0.3.1 -> 0.3.5
* Bump referenced cluster module in /docker-openvpn-server: 0.3.2 -> 0.3.5

v1.0.1

Improvemnts:
* `docker-openvpn-server/cluster` - Configurable `hc_grace_period` for the ASG cluster.

Fixes:
* `docker-openvpn-server/cluster` - Restore outputs for
`vpn_server_sg_id` and `role_id_openvpn`
* `docker-openvpn-server` - Restore outputs for
`vpn_server_sg_id`, `role_id_openvpn`, `vpn_whitelist`,
`vpn_lb_dns_name`, and `vpn_lb_zone_id`
* `docker-openvpn-server/cluster` - Better defaults for cidr_routes to not break terraform interpolation.
* `docker-openvpn-server/cluster` - More tolerant version requirements for terraform template