Use |- literal syntax for long strings

def literal_unicode_representer(dumper, data):
    """
    Use |- literal syntax for long strings
    """
    if '\n' in data:
        return dumper.represent_scalar(u'tag:yaml.org,2002:str', data, style='|')
    else:
        return dumper.represent_scalar(u'tag:yaml.org,2002:str', data)