Fix error in RouterMixin doc

Author: chollier

lib/RouterMixin.js

@@ -129,6 +129,7 @@ var RouterMixin = {
    * Navigate to a path
    *
    * @param {String} path
+   * @param {Function} navigation
    * @param {Callback} cb
    */
   navigate: function(path, navigation, cb) {
@@ -149,7 +150,7 @@ var RouterMixin = {
    * @private
    *
    * @param {String} path
-   * @param {String} path
+   * @param {Function} navigation
    * @param {Callback} cb
    */
   setPath: function(path, navigation, cb) {