Try 2

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Point in Polygon</title>
  
  <meta name='viewport' content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no' />
  <script src='https://api.tiles.mapbox.com/mapbox.js/v1.4.2/mapbox.js'></script>
  <link href='https://api.tiles.mapbox.com/mapbox.js/v1.4.2/mapbox.css' rel='stylesheet' />
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script> 
  
  <style>
    body { margin:0; padding:0; }
    #map { position:absolute; top:0; bottom:0; width:100%; }
  </style>
</head>
<body>
<style>
#state {
    position:absolute;
    top:10px;
    right:10px;
    background:#fff;
    font-size:30px;
    padding:10px;
    z-index:999;
}
</style>

$.ajax({
    url: 'map.geojson',
    dataType: 'json',
    success: function load(d) {
        var states = L.geoJson(d).addTo(map);
        L.marker([44.4758825, -73.212072], {
            icon: L.mapbox.marker.icon({
                'marker-color': '#f22',
                'marker-size': 'large',
                'marker-symbol': 'circle-stroked'
            }),
            draggable: true
        }).addTo(map)
        .on('dragend', function(e) {
            var layer = leafletPip.pointInLayer(this.getLatLng(), states, true);
            document.getElementById('state').innerHTML = layer.length ?
                layer[0].feature.properties.name : '';
        });
    }
});
</script>
</body>
</html>

Modified http://api.tiles.mapbox.com/mapbox.js/v1.4.2/mapbox.js to a secure url

Modified http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js to a secure url

https://api.tiles.mapbox.com/mapbox.js/v1.4.2/mapbox.js

https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js

https://www.mapbox.com/mapbox.js/assets/leaflet-pip.js