title: Summernote Toolbar customization Issue
body: <p>I'm trying to delete some features from summernote editor toolbar. But when I write following code to customize it,</p>
  
  <pre><code>$('.summernote').summernote({
  
    toolbar: [
      // [groupName, [list of button]]
      ['style', ['bold', 'italic', 'underline', 'clear']],
      ['font', ['strikethrough', 'superscript', 'subscript']],
      ['fontsize', ['fontsize']],
      ['color', ['color']],
      ['para', ['ul', 'ol', 'paragraph']],
      ['height', ['height']]
    ]
  });
  </code></pre>
  
  <p>it gives given below error in console (developer tools) and toolbar disappears (because of error).</p>
  
  <pre><code>Uncaught TypeError: b[t[1][u]] is not a function
  </code></pre>