Unparse indent not included in 0.13.0 release?

[AlbertoV5]

Hello. Thanks a lot for this great module.

I'm using version 0.13.0 from PyPi and it doesn't include support for unparse indent with an integer, from this PR: #222

I'm not sure what the timeline in the release and the PR merge was but I'm guessing it will come in the next release then?

Just wanted to make sure. Thank you.

def test_unparse_indent():
    """
    pip freeze | grep xmltodict
    xmltodict==0.13.0
    """
    import xmltodict
    import logging
    log = logging.getLogger(__name__)
    d = xmltodict.parse(
    """<a>
        <b>
        <!-- b comment -->
        <c>
            <!-- c comment -->
            1
        </c>
        <d>2</d>
        </b>
    </a>
    """
    )
    log.debug(xmltodict.unparse(d, pretty=True, indent="  "))
    """
    <?xml version="1.0" encoding="utf-8"?>
    <a>
      <b>
        <c>1</c>
        <d>2</d>
      </b>
    </a>
    """
    log.debug(xmltodict.unparse(d, pretty=True, indent=2))
    """"TypeError: decoding to str: need a bytes-like object, int found"""