Revert "support CNAME if entry is not all digits"

Alias only support A records

This reverts commit fad159b.

Author: wesleung

main.tf

@@ -14,7 +14,7 @@ resource "aws_route53_record" "default" {
   count   = "${module.enabled.value ? length(compact(var.aliases)) : 0}"
   zone_id = "${data.aws_route53_zone.default.zone_id}"
   name    = "${element(compact(var.aliases), count.index)}"
-  type    = "${(upper(var.target_dns_name) == var.target_dns_name && lower(var.target_dns_name) == var.target_dns_name) ? "A" : "CNAME"}"
+  type    = "A"
 
   alias {
     name                   = "${var.target_dns_name}"