Print a warning message on the rich text view

def warning(message, css_path=CSS_PATH):
    """Print a warning message on the rich text view"""
    env = Environment()
    env.loader = FileSystemLoader(osp.join(CONFDIR_PATH, 'templates'))
    warning = env.get_template("warning.html")
    return warning.render(css_path=css_path, text=message)