title: Mapbox issue with parsing json data for heatmap
body: <p>My code is this     </p>
  
  <pre><code>heat = L.heatLayer([], { maxZoom: 12 }).addTo(map);
   $.getJSON("js/example-single.geojson", function(data) {
      var geojsosn = L.geoJson(data, {
        onEachFeature: function (feature, layer) {
            console.log(feature.geometry.coordinates[0] ,feature.geometry.coordinates[1]);
          heat.addLatLng(feature.geometry.coordinates[0], feature.geometry.coordinates[1]);
  
        }
      });
  </code></pre>
  
  <p>but am getting an error "Uncaught TypeError: Cannot read property 'lat' of undefined" </p>
  
  <p>please tell how to fix this, if my code is wrong somebody show me how to parse json data for heat map in mapbox</p>
  
  <p>my json data is </p>
  
  <pre><code>{ "type": "FeatureCollection",
    "features": [
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [13.353323936462402, 38.11200434622822]},
        "properties": {"marker-color": "#000"}
      }
    ]
  }
  </code></pre>