title: Remove Leaflet minicharts
body: <p>I've created piecharts with the <strong>Leaflet.minicharts.js</strong> plugin. 
  It works fine to add the charts. 
  But I can't remove them anymore.
  I tried to remove each chart separately with <code>map.removeLayer(chart[i])</code>.
  And I also tried to put all charts together in a LayerGroup and then use the function <code>map.removeLayer(LayerGroup)</code> and with <code>layergorup.clearLayers()</code>. When I call the function <code>map.hasLayer(layer)</code>, it returns <code>false</code>. So, everything as expected. But the charts are still visible on the map.
  Here a simple example with a barchart, which I try to remove with a button-click.</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
      &lt;title&gt;Leaflet Test&lt;/title&gt;
      &lt;link rel="stylesheet" href="https://unpkg.com/leaflet@1.1.0/dist/leaflet.css"
     integrity="sha512-wcw6ts8Anuw10Mzh9Ytw4pylW8+NAD4ch3lqm9lzAsTxg0GFeJgoAtxuCLREZSC5lUXdVyo/7yfsqFjQ4S+aKw=="
     crossorigin=""/&gt;
      &lt;script src="https://unpkg.com/leaflet@1.1.0/dist/leaflet.js"
     integrity="sha512-mNqn2Wg7tSToJhvHcqfzLMU6J4mkOImSPTxVZAdo+lcPlk+GhZmYgACEe0x35K7YzW1zJ7XyJV/TT1MrdXvMcA=="
     crossorigin=""&gt;&lt;/script&gt;
     &lt;script src="https://unpkg.com/leaflet.minichart/dist/leaflet.minichart.min.js" charset="utf-8"&gt;&lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
      &lt;!-- CSS --&gt;
      &lt;style type="text/css"&gt;
          #mapid { height: 480px; }
          #butt {color:black;position: absolute;padding:2em;top:50%; left:50%;}
      &lt;/style&gt;
  
      &lt;div id="mapid"&gt;&lt;/div&gt;
      &lt;button id="butt" onclick="vanish();"&gt;Remove Chart!&lt;/button&gt;
      &lt;script type="text/javascript"&gt;
          var map = L.map('mapid').setView([50, 9], 14);
          var tiles = L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
              attribution: '&amp;copy; &lt;a href="http://osm.org/copyright"&gt;OpenStreetMap&lt;/a&gt; contributors',
          }).addTo( map );
  
          var center = [50, 9];
          function fakeData() {           
            return [Math.random(), Math.random(), Math.random()];
          }        
  
          var myBarChart = L.minichart(center, {data: fakeData()});
          map.addLayer(myBarChart);
  
  
          function vanish(e) {
              console.log(map.hasLayer(myBarChart));
              map.removeLayer(myBarChart);
              console.log(map.hasLayer(myBarChart));
          }
  
      &lt;/script&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>