Make sure Terraform scripts are using "Cloud Foundation Toolkit" templates

[mithro]

From https://cloud.google.com/foundation-toolkit

Cloud Foundation Toolkit provides a series of reference templates for Deployment Manager and Terraform which reflect Google Cloud best practices. These templates can be used off-the-shelf to quickly build a repeatable enterprise-ready foundation in Google Cloud. This frees you to focus on deploying your applications on this baseline secure environment. And with infrastructure as code (IaC), you can easily update the foundation as your needs change.

We should thus make sure that we are using these templates in this repository.