Don't put .expander class on a column if it has a nested row

lib/makeColumn.js

@@ -12,6 +12,7 @@ module.exports = function(col) {
   var output  = '';
   var inner   = $(col).html();
   var classes = [];
+  var thClass = '';
 
   // Add 1 to include current column
   var colCount = $(col).siblings().length + 1;
@@ -32,16 +33,21 @@ module.exports = function(col) {
   if (!$(col).prev(this.components.columns).length) classes.push('first');
   if (!$(col).next(this.components.columns).length) classes.push('last');
 
+  // If the column contains a nested row, the .expander class should not be used
+  if (!col.find('.row, row').length) {
+    thClass = ' class="expander"';
+  }
+
   // Final HTML output
   output = multiline(function() {/*
     <th class="%s">
       <table>
         <tr>
-          <th class="expander">%s</th>
+          <th%s>%s</th>
         </tr>
       </table>
     </th>
   */});
 
-  return format(output, classes.join(' '), inner);
+  return format(output, classes.join(' '), thClass, inner);
 }