title: MapBox clear all current markers
body: <p>I've created a MapBox instance with:</p>
  
  <pre><code>var map = new mapboxgl.Map({
      container : 'map',
      style : 'mapbox://styles/mapbox/streets-v9'
  });
  </code></pre>
  
  <p>I need to clear all markers, and have tried things like map.remove(marker) on each one, and a few other things, but nothing seems to work. </p>
  
  <p>Is there a simple function call to just clear all markers from the map?</p>
  
  <p>EDIT: Different from <a href="https://stackoverflow.com/questions/28646317/how-to-remove-all-layers-and-features-from-map">How to remove all layers and features from map?</a> because I get "eachLayer is not a recognised function" (or similar) in console.</p>