Add extra tags for DHCP option set (#42)

main.tf

@@ -22,7 +22,7 @@ resource "aws_vpc_dhcp_options" "this" {
   netbios_name_servers = "${var.dhcp_options_netbios_name_servers}"
   netbios_node_type    = "${var.dhcp_options_netbios_node_type}"
 
-  tags = "${merge(var.tags, map("Name", format("%s", var.name)))}"
+  tags = "${merge(var.tags, var.dhcp_options_tags, map("Name", format("%s", var.name)))}"
 }
 
 ###############################

variables.tf

@@ -135,6 +135,11 @@ variable "elasticache_subnet_tags" {
   default     = {}
 }
 
+variable "dhcp_options_tags" {
+  description = "Additional tags for the DHCP option set"
+  default     = {}
+}
+
 variable "enable_dhcp_options" {
   description = "Should be true if you want to specify a DHCP options set with a custom domain name, DNS servers, NTP servers, netbios servers, and/or netbios server type"
   default     = false