title: MapBox GeoJSON clear all markers?
body: <p>I would like to update my map with "new" markers. So reset all visible markers first. Ill read my markers by geoJSON by Ajax with:</p>
  
  <pre><code>   $.ajax({
          url: 'dashboard/geoJSON',
          dataType: 'json',
          async: false,
          type: 'GET',
          success: function(geojson) {
              var locations = L.mapbox.featureLayer().addTo(map);
              locations.setGeoJSON(geojson); 
              // reset?
  
           }
      });
  </code></pre>
  
  <p>Ill tried with:</p>
  
  <pre><code>L.mapbox.featureLayer().clearLayers();
  </code></pre>
  
  <p>To reset before adding all new markers, but it is not working. Any ideas?</p>