code: function removeClass(el, className) {
      if (!el || !className) {
        return;
      }
      el.className = el.className.replace(new RegExp('(?:^|\\s)' + className + '(?!\\S)'), '');
      return el;
    }
docs: Removes class from element
  @param  {Object} el
  @param  {String} className
  @return {Object}