Enable CoreDNS loop and loadbalance plugins

* loop sends an initial query to detect infinite forwarding
loops in configured upstream DNS servers and fast exit with
an error (its a fatal misconfiguration on the network that
will otherwise cause resolvers to consume memory/CPU until
crashing, masking the problem)
* https://github.com/coredns/coredns/tree/master/plugin/loop
* loadbalance randomizes the ordering of A, AAAA, and MX records
in responses to provide round-robin load balancing (as usual,
clients may still cache responses though)
* https://github.com/coredns/coredns/tree/master/plugin/loadbalance

google-cloud/fedora-atomic/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=d045a8e6b8eccfbb9d69bb51953b5a93d23f67f7"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=3f3ab6b5c07f606e2c0cc6a096887962172a2680"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]