Updates syntax to be compatible with TF 0.12+
terraform-cloudhealth-iam >= v0.1.0 - Requires Terraform >= 0.12
terraform-cloudhealth-iam <= v0.0.18 - Requires Terraform <= 0.11
terraform-cloudhealth-iam >= v0.1.0 - Requires Terraform >= 0.12
terraform-cloudhealth-iam <= v0.0.18 - Requires Terraform <= 0.11