Fix masterVersion missing import
Add dbUsername config to the readme
MODIFY
gcp-ts-k8s-ruby-on-rails-postgresql/infra/cluster.ts
gcp-ts-k8s-ruby-on-rails-postgresql/infra/cluster.ts
import * as gcp from "@pulumi/gcp";
import * as k8s from "@pulumi/kubernetes";
import * as pulumi from "@pulumi/pulumi";
-import { clusterNodeCount, clusterNodeMachineType, clusterPassword, clusterUsername } from "./config";
+import { clusterNodeCount, clusterNodeMachineType, clusterPassword, clusterUsername, masterVersion } from "./config";
// Create the GKE cluster and export it.
export const cluster = new gcp.container.Cluster("gke-cluster", {

Fix masterVersion missing import
Add dbUsername config to the readme