Installation on popular cloud servers invalidates Questtrade key

[jonathanbell]

The Questrade package writes the Questrade key to disk on the file system for data storage:

Questrade.prototype._saveKey = function (cb) {
  cb = cb || function(){};
  var self = this;
  fs.writeFile(self._getKeyFile(), self.refreshToken, 'utf8', function (err) {
    if (err) return cb({ message: 'failed_to_write', details: err });
    cb(null, self.refreshToken);
  });
}

If running on a service like Heroku with an ephemeral file system, the data will not persist and the API key will not be valid. TODO: Write the temp key to a database and retrieve it when requested by the Questrade package.