Add mac builds, speed up win builds (#72)
Add mac builds, speed up win builds (#72)

* Add mac builds, speed up win builds

Closes #65

* bump xcode to 12.0.0

Co-authored-by: Radek Simko <c0f89f684c2e56811603206eabe5a4cea7f58f3e@gmail.com>
hashicorp/terraform-exec,hashicorp/terraform-exec