function utm(query){
  if ('?' == query.charAt(0)) query = query.substring(1);
  var query = query.replace(/\?/g, '&');
  var params = parse(query);
  var param;
  var ret = {};

  for (var key in params) {
    if (~key.indexOf('utm_')) {
      param = key.substr(4);
      if ('campaign' == param) param = 'name';
      ret[param] = params[key];
    }
  }

  return ret;
}
Get all utm params from the given `querystring`

@param {String} query
@return {Object}
@api private