mapboxgl.GeoJSONSource is not a constructor

[CodeLords]

I want to move a marker in particular direction and got this error. Source Below mentioned.

<title></title> <script src='https://api.tiles.mapbox.com/mapbox-gl-js/v0.12.0/mapbox-gl.js'></script> <style> body { margin:0; padding:0; } #map { position:absolute; top:0; bottom:0; width:100%; } </style>

<script>

mapboxgl.accessToken = 'ApiKey';
var map = new mapboxgl.Map({
container: 'map',
style: 'mapbox://styles/mapbox/satellite-hybrid-v8',
center: [-86.155231, 39.768458],
zoom: 6
});

var direction = 0, manual = false, speed = 0.1;

// create a GeoJSON point to serve as a starting point
var point = {
"type": "Point",
"coordinates": [-86.155231, 39.768458]
};

// add the GeoJSON above to a new vector tile source
var source = new mapboxgl.GeoJSONSource({
data: point
});

function setPosition() {
point.coordinates[0] += speed * Math.sin(direction) / 100;
point.coordinates[1] += speed * Math.cos(direction) / 100;
source.setData(point);

map.setLayoutProperty('drone', 'icon', direction * (180 / Math.PI));

if (!manual && Math.random() > 0.95) {
    direction += (Math.random() - 0.5) / 2;
}

map.setCenter(point.coordinates);

}

map.on('style.load', function () {
map.addSource('drone', source);

map.addLayer({
    "id": "drone-glow-strong",
    "type": "circle",
    "source": "drone",
    "paint": {
        "circle-radius": 18,
        "circle-color": "#00e673",
        "circle-opacity": .8
    }
});

map.addLayer({
    "id": "drone-glow",
    "type": "circle",
    "source": "drone",
    "paint": {
        "circle-radius": 40,
        "circle-color": "#99ffcc",
        "circle-opacity": 0.4
    }
});

// Full icon list: https://www.mapbox.com/maki
map.addLayer({
    "id": "drone",
    "type": "symbol",
    "source": "drone",
    "layout": {
        "icon-image": "car-24",  // try: 'car-24', 'airport-24', 'zoo-24'
    }
});

window.setInterval(setPosition, 10);

});

// Add manual control of the airplane with left and right arrow keys, just because
document.body.addEventListener('keydown', function (e) {
if (e.which == 37) { // left
direction -= 0.1;
manual = true;
}
if (e.which == 39) { // right
direction += 0.1;
manual = true;
}
if (e.which == 38) { // faster
speed = Math.min(speed + 0.1, 10);
manual = true;
e.preventDefault();
}
if (e.which == 40) { // slower
speed = Math.max(speed - 0.1, 0);
manual = true;
e.preventDefault();
}
}, true);
</script>