title: Street labels in Mapbox Tile Layer too small
body: <p>I have the following Leaflet map: <a href="https://jsfiddle.net/zq02pnpg/1/" rel="noreferrer">JSFiddle link</a></p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div id="mapid" style="height: 300px;"&gt;&lt;/div&gt;
  
  &lt;script&gt;
    var mapboxTiles = L.tileLayer(mapBoxUrl, {
      attribution: attributionText
    });
  
    var map = L.map('mapid')
      .addLayer(mapboxTiles)
      .setView([42.888284, -78.877222], 16);
  
  &lt;/script&gt;
  </code></pre>
  
  <p>The font size for the street labels is very small, to the point of being unreadable, and when you zoom in, the font size gets smaller.  Is there a way to control the font size?</p>