index.js
function (data, arr, options) {
  return arr.map(function(lookup) {
    return expander.process(data, lookup, options);
  });
}
function (data, arr, options) {
  return arr.map(function(lookup) {
    return expander.process(data, lookup, options);
  });
}
recursively expand an array until it doesn't contain any template strings