Refactor: google_container_cluster

- Refactor provider block to use variable for project and region
- Update node_config to use variable for machine_type
- Add google_container_cluster resource for my-cluster
- set variables for project,region,machine_type,username and password
- Add variables.tf file for setting project,region,machine_type,username and password dynamically

terraform-gke/variables.tf

@@ -0,0 +1,25 @@
+# You will need to define those variables in your variables.tf, and use terraform apply -var 'google_region=us-central1' -var 'machine_type=n1-standard-1' -var 'username=admin' -var 'password=password' to set them when you run terraform apply.
+
+variable "my-project-id" {
+  type = string
+}
+
+variable "my-cluster" {
+  type = string
+}
+
+variable "google_region" {
+  type = string
+}
+
+variable "machine_type" {
+  type = string
+}
+
+variable "username" {
+  type = string
+}
+
+variable "password" {
+  type = string
+}