Upgrade to terraform 0.12

Resolves #291

Terraform/outputs.tf

@@ -1,31 +1,32 @@
-output region {
-  value = "${var.region}"
+output "region" {
+  value = var.region
 }
 
 output "logger_public_ip" {
-  value = "${aws_instance.logger.public_ip}"
+  value = aws_instance.logger.public_ip
 }
 
 output "dc_public_ip" {
-  value = "${aws_instance.dc.public_ip}"
+  value = aws_instance.dc.public_ip
 }
 
 output "wef_public_ip" {
-  value = "${aws_instance.wef.public_ip}"
+  value = aws_instance.wef.public_ip
 }
 
 output "win10_public_ip" {
-  value = "${aws_instance.win10.public_ip}"
+  value = aws_instance.win10.public_ip
 }
 
 output "ata_url" {
-  value = "${local.ata_url}"
+  value = local.ata_url
 }
 
 output "fleet_url" {
-  value = "${local.fleet_url}"
+  value = local.fleet_url
 }
 
 output "splunk_url" {
-  value = "${local.splunk_url}"
+  value = local.splunk_url
 }
+