fix request url when still no notificationId received

lib/api.js

@@ -88,16 +88,15 @@ API.prototype._fetchLatestNotifications = function(interval, cb) {
 
   cb = cb || function() {};
 
-  var url = '/v1/notifications/';
-  if (self.lastNotificationId) {
-    url += '?notificationId=' + self.lastNotificationId;
-  } else {
-    url += '?timeSpan=' + (interval + 2); // Give a couple of seconds for network latency
+  var opts = {
+    lastNotificationId: self.lastNotificationId,
+  };
+
+  if (!self.lastNotificationId) {
+    opts.timeSpan = interval + 2; // Give a couple of seconds for network latency
   }
 
-  self.getNotifications({
-    lastNotificationId: self.lastNotificationId
-  }, function(err, notifications) {
+  self.getNotifications(opts, function(err, notifications) {
     if (err) {
       log.warn('Error receiving notifications.');
       log.debug(err);
@@ -1060,14 +1059,21 @@ API.prototype._processCustomData = function(result) {
  *
  * @param {object} opts
  * @param {String} lastNotificationId (optional) - The ID of the last received notification
+ * @param {String} timeSpan (optional) - A time window on which to look for notifications (in seconds)
  * @returns {Callback} cb - Returns error or an array of notifications
  */
 API.prototype.getNotifications = function(opts, cb) {
   $.checkState(this.credentials);
 
   var self = this;
+  opts = opts || {};
+
   var url = '/v1/notifications/';
-  if (opts.lastNotificationId) url += '?notificationId=' + opts.lastNotificationId;
+  if (opts.lastNotificationId) {
+    url += '?notificationId=' + opts.lastNotificationId;
+  } else if (opts.timeSpan) {
+    url += '?timeSpan=' + opts.timeSpan;
+  }
 
   self._doGetRequest(url, function(err, result) {
     if (err) return cb(err);