title: plotly js remove title and title area
body: <p>How does on remove the title from a plotly js chart?</p>
  
  <p>Example chart I have is as follows</p>
  
  <pre><code>&lt;head&gt;
       &lt;script src="https://cdn.plot.ly/plotly-latest.min.js"&gt;&lt;/script&gt;
  &lt;/head&gt;
  &lt;div id="myDiv" style="width: 800px; height: 400px;"&gt;&lt;/div&gt;
  &lt;script&gt;
  
  var trace1 = {
     x: [1, 2, 3, 4],
     y: [10, 15, 13, 17],
     mode: 'markers'
  };
  
  var trace2 = {
    x: [2, 3, 4, 5],
    y: [16, 5, 11, 9],
    mode: 'lines'
  };
  
  var trace3 = {
    x: [1, 2, 3, 4],
    y: [12, 9, 15, 12],
    mode: 'lines+markers'
  };
  
  var data = [ trace1, trace2, trace3 ];
  
  var layout = {
    title:false
  };
  
  Plotly.newPlot('myDiv', data, layout);
  &lt;/script&gt;
  </code></pre>
  
  <p>This chart will have a title "false", I have also tried
      var layout = {
          showtitle:false
      }</p>
  
  <p>setting the title to null: <code>title:''</code> or simply removing the title line, doesn't display a title, but the title area which is approxiamtely 50px in height above the chart reserved for the title remains, how do I remove this title area?</p>