code: def ci_macos():
      
      run_command("brew install $PYTHON pipenv || echo \"Installed PipEnv\"")
      command_string = "sudo -H $PIP install "
      for element in DEPENDENCIES + REQUIREMENTS + ["-U"]:
          command_string += element + " "
      run_command(command_string)
      # Build a wheel
      run_command("sudo -H $PYTHON setup.py bdist_wheel")
      assert check_wheel_existence()
      exit(0)
docs: Setup Travis-CI macOS for wheel building