Use the new "remove_default_node_pool" option.

In the provider, #1245 was merged which allows us to remove the default
node pool on cluster creation. Now, we just have to specify the default
node pool name (the one which gets destroyed).

hashicorp/terraform-provider-google#1245

gke.tf

@@ -5,15 +5,13 @@ provider "google" {
 }
 
 resource "google_container_cluster" "primary" {
-  name               = "gke-example"
-  zone               = "europe-west2-a"
+  name                     = "gke-example"
+  zone                     = "europe-west2-a"
+  remove_default_node_pool = true
 
-  /*
-  node_pool = [{
-    name       = "default-pool"
-    node_count = 0
-  }]
-  */
+  node_pool {
+    name = "default-pool"
+  }
 }
 
 resource "google_container_node_pool" "primary_pool" {
@@ -35,19 +33,4 @@ resource "google_container_node_pool" "primary_pool" {
     auto_repair  = true
     auto_upgrade = true
   }
-
-  # Delete the default node pool before spinning this one up
-  depends_on = ["null_resource.default_cluster_deleter"]
-}
-
-resource "null_resource" "default_cluster_deleter" {
-  provisioner "local-exec" {
-    command = <<EOF
-    gcloud container node-pools \
-      --project terraform-gke \
-      --quiet \
-      delete default-pool \
-      --cluster ${google_container_cluster.primary.name}
-EOF
-  }
 }