Feature/validate requirements script

[mauro-cit]

This PR is adding a script that will make sure to validate wheter the environment that will run the terraform foundation steps are configured with the expected requirements. These requirements are:

• Checking if the machine have installed: Git, Terraform and gcloud sdk
• Check if the version of git and gcloud sdk are above a minimum expected
• Check if Terraform version is exact the one expected
• Check if the user have runned gcloud auth login and gcloud auth application-default login locally with a valid account
• Check if the end user credential that will be used to run the terraform scripts contains the required Organization and Billing account level roles
• Check if the bootstrap terraform.tfvars is found and have the required values correctly filled

[bharathkkb]

Thanks for the PR @mauro-cit

[bharathkkb]

@mauro-cit It will be good to follow up with updating docs to let users know about the script.