add terraform-tools to the docker images

[daniel-cit]

Fixes #185

[comment-bot-dev]

@daniel-cit
Thanks for the PR! 🚀
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[bharathkkb]

Lets also add to the older cloudbuild module?
https://github.com/terraform-google-modules/terraform-google-bootstrap/blob/master/modules/cloudbuild/cloudbuild_builder/Dockerfile

[daniel-cit]

Lets also add to the older cloudbuild module? https://github.com/terraform-google-modules/terraform-google-bootstrap/blob/master/modules/cloudbuild/cloudbuild_builder/Dockerfile

@bharathkkb it has also ben added.

In the older module it is a bit different, it uses google-cloud-sdk-terraform-tools instead of just terraform-tools because they use different base images