Use local module for safer cluster example.

Author: morgante

examples/safer_cluster_iap_bastion/cluster.tf

@@ -15,8 +15,8 @@
  */
 
 module "gke" {
-  source                  = "terraform-google-modules/kubernetes-engine/google//modules/safer-cluster"
-  version                 = "~> 9.0"
+  source = "../../modules/safer-cluster"
+
   project_id              = module.enabled_google_apis.project_id
   name                    = var.cluster_name
   region                  = var.region