* Calico on GCE with IP-in-IP encapsulation and MTU 1440
* Calico on DO with IP-in-IP encapsulation and MTU 1440
* Digital Ocean firewalls don't support IPIP protocol yet
* In terraform-provider-google v0.1.3, it is no longer neccessary
to supply a (duplicated) value for the instance_template field
automatic_restart
* Previously this field was set to match the scheduling
automatic_restart since the field defaulted to true and would
cause plan to always show changes were needed
* Remove k8s_domain_name input variable, the controller DNS
record will be "${var.cluster_name}.${dns_zone}"
* Rename dns_base_zone to dns_zone
* Rename dns_base_zone_name to dns_zone_name
