Change loaded version to the stable release (3.18) version of Google API
Change loaded version to the stable release (3.18) version of Google API

The version we load should be 3.18, which is the stable release version of the API. See the [API reference](https://developers.google.com/maps/documentation/javascript/reference) for more information on this version.
Carrooi/Js-GoogleMapsLoader,hollandmatt/Js-GoogleMapsLoader,huyby/Js-GoogleMapsLoader,hollandmatt/Js-GoogleMapsLoader,Carrooi/Js-GoogleMapsLoader,huyby/Js-GoogleMapsLoader,Carrooi/Node-GoogleMaps,Carrooi/Node-GoogleMaps