code: function execAnySubFns(actions) {
    return actions.map(function (action) {
      return Object.keys(action).reduce(function (accum, key) {
        // if it is list of sub keys, and is a fn, then bind with tokens
        if (SUBSTITUTED_KEYS.indexOf(key) !== -1 && typeof action[key] === 'function') {
          accum[key] = action[key](); // exec fn to get value
        } else {
          accum[key] = action[key];
        }
        return accum;
      }, {});
    });
  }
docs: If any substitutions need to be done, the properties will be
  replaced with a fn which has been bound to tokens, so exec the
  fn and return the value for the property
  @returns actions with values ready for use