Example usage : we want our nodes to be able to update route53 record
for using external-dns.
```hcl
data "template_file" "eks_worker_additional_route53_policy" {
template = "${file("iam/route53_policy.json.tpl")}"
}
resource "aws_iam_policy" "eks_worker_additional_route53_policy" {
description = "Allow nodes to update our zone"
name = "${module.k8s_cluster01_label.id}-additional-route53-policy"
policy = "${data.template_file.eks_worker_additional_route53_policy.rendered}"
}
```
which defines the policy; then in the EKS module :
```hcl
module "cluster01" {
cluster_name = "cluster01"
<snip>
workers_addtional_policies = [
"${aws_iam_policy.eks_worker_additional_route53_policy.arn}"
]
workers_addtional_policies_count = 1
<snip>
```
