rel-urls use first value instead of last one

[kartikprabhu]

<a href="#a" rel="a" hreflang="de"></a>
<a href="#a" rel="a" hreflang="en"></a>

gives

    "rel-urls": {
        "#a": {
            "rels": [
                "a"
            ], 
            "text": "", 
            "hreflang": "en"
        }
    }

should give

    "rel-urls": {
        "#a": {
            "rels": [
                "a"
            ], 
            "text": "", 
            "hreflang": "de"
        }
    }

line: https://github.com/kartikprabhu/mf2py/blob/master/mf2py/parser.py#L357

[kartikprabhu]

fixed in experimental

[kartikprabhu]

done in version 1.1.1 https://github.com/kartikprabhu/mf2py/releases/tag/1.1.1