Rename Fedora CoreOS fcc directory to butane

* Align both Fedora CoreOS and Flatcar Linux keeping Butane
Configs in a directory called butane

aws/fedora-coreos/kubernetes/controllers.tf

@@ -49,7 +49,7 @@ resource "aws_instance" "controllers" {
 # Fedora CoreOS controllers
 data "ct_config" "controllers" {
   count = var.controller_count
-  content = templatefile("${path.module}/fcc/controller.yaml", {
+  content = templatefile("${path.module}/butane/controller.yaml", {
     # Cannot use cyclic dependencies on controllers or their DNS records
     etcd_name   = "etcd${count.index}"
     etcd_domain = "${var.cluster_name}-etcd${count.index}.${var.dns_zone}"

aws/fedora-coreos/kubernetes/workers/workers.tf

@@ -70,7 +70,7 @@ resource "aws_launch_configuration" "worker" {
 
 # Fedora CoreOS worker
 data "ct_config" "worker" {
-  content = templatefile("${path.module}/fcc/worker.yaml", {
+  content = templatefile("${path.module}/butane/worker.yaml", {
     kubeconfig             = indent(10, var.kubeconfig)
     ssh_authorized_key     = var.ssh_authorized_key
     cluster_dns_service_ip = cidrhost(var.service_cidr, 10)