terraform 0.11 cause 0.12 breaks

outputs.tf

 output "id" {
-  value = cloudflare_zone.dns_zone.*.id
+  value = "${cloudflare_zone.dns_zone.*.id}"
 }
 
 output "vanity_name_servers" {
-  value = cloudflare_zone.dns_zone.*.vanity_name_servers
+  value = "${cloudflare_zone.dns_zone.*.vanity_name_servers}"
 }
 
 # does not work
@@ -17,14 +17,13 @@ output "vanity_name_servers" {
 # }
 
 output "status" {
-  value = cloudflare_zone.dns_zone.*.status
+  value = "${cloudflare_zone.dns_zone.*.status}"
 }
 
 output "type" {
-  value = cloudflare_zone.dns_zone.*.type
+  value = "${cloudflare_zone.dns_zone.*.type}"
 }
 
 output "name_servers" {
-  value = cloudflare_zone.dns_zone.*.name_servers
+  value = "${cloudflare_zone.dns_zone.*.name_servers}"
 }
-

variables.tf

-variable "zone" {
-}
+variable "zone" {}
 
 variable "create_zone" {
   default = "false"
 }
-

zone.tf

 resource "cloudflare_zone" "dns_zone" {
-  count = var.create_zone == "true" ? 1 : 0
-  zone  = var.zone
+  count = "${var.create_zone == "true" ? 1 : 0}"
+  zone  = "${var.zone}"
 }
-