Update README on how to execute TestUp CI commands from macOS.
Update README on how to execute TestUp CI commands from macOS.

thomthom/testup-2,thomthom/testup-2,thomthom/testup-2,SketchUp/testup-2,thomthom/testup-2,SketchUp/testup-2,SketchUp/testup-2,SketchUp/testup-2,thomthom/testup-2,thomthom/testup-2,SketchUp/testup-2,SketchUp/testup-2