isDivider = function (operator, next, previous) {
  if (operator === '/') {

    // Catch the following:
    // .foo {
    //   property: calc(100% / 2);
    // }
    if (previous && next) {
      if (previous.is('dimension') && (next.is('dimension') || next.is('number'))) {
        return true;
      }
    }
  }

  return false;
}
Determine if operator is divider

@param {string} operator - The operator
@param {Object} next - The next node
@param {Object} previous - The previous node
@returns {bool} true / false