title: Add custom bindTooltip class
body: <p>I am trying to add custom class to my bindTooltip but the new class do not show up. My method based on <a href="https://gis.stackexchange.com/questions/212820/overriding-leaflet-tooltip-style">this</a> question. </p>
  
  <p>My custom popup class is working fine but if I want to overwrite the tooltip class than it is now working. </p>
  
  <p><strong>My JS code:</strong></p>
  
  <pre><code> var PopupClass={'className': 'class-popup'}
   var TooltipClass={'className': 'class-tooltip'}
  
  L.marker(
    [46.17319713, 21.34458608],
    {icon: OnlineMarker}
  ).bindPopup(
    'Test Popup', 
    PopupClass
  ).bindTooltip(
    'Test Tooltip',
    {direction: 'top', permanent: true, offset: [10,0]}, 
    TooltipClass
  ).addTo(MyMap)
  </code></pre>
  
  <p><strong>My CSS code:</strong></p>
  
  <pre><code>/* popup-class*/
  
  .class-popup .leaflet-popup-content-wrapper {
    background:#2980b9;
    color:#fff;
    font-size:10px;
    line-height:10px;
    }
  
  .class-popup .leaflet-popup-content-wrapper a {
    color:#2980b9;
    }
  .class-popup .leaflet-popup-tip-container {
    width:40px;
    height:20px;
    }
  .class-popup .leaflet-popup-tip {
    background:#2980b9;
    }
  
  /* tooltip-class*/ 
  
  .class-tooltip{
    background: green;
    border: 2px solid cyan
  }
  .leaflet-tooltip-left.class-tooltip::before {
    border-left-color: cyan;
  }
  .leaflet-tooltip-right.class-tooltip::before {
    border-right-color: cyan;
  }
  </code></pre>