fix(versions): be more broad in the versions we accept

For terraform modules we generally should only ever specify *minimum*
versions. From the docs[1]:

> Reusable modules should constrain only their minimum allowed versions
> of Terraform and providers, such as >= 0.12.0. This helps avoid known
> incompatibilities, while allowing the user of the module flexibility
> to upgrade to newer versions of Terraform without altering the module.

[1] https://developer.hashicorp.com/terraform/language/expressions/
  version-constraints#best-practices