Shows user notification message via `terminal-notifier` command.

        `title`
            Notification title.
        `message`
            Notification message.

def _terminal_notifier(title, message):
    """ Shows user notification message via `terminal-notifier` command.

        `title`
            Notification title.
        `message`
            Notification message.
        """

    try:
        paths = common.extract_app_paths(['terminal-notifier'])
    except ValueError:
        pass

    common.shell_process([paths[0], '-title', title, '-message', message])