Build a template from the source template directories.

    :param template_directories: source template directories
    :return: template workflow

def build(template_directories):
    """
    Build a template from the source template directories.

    :param template_directories: source template directories
    :return: template workflow
    """
    template = load_template(template_directories[0])
    for directory in template_directories[1:]:
        template.update(load_template(directory))
    return template