This one was bugging me too because I was in your same boat. I copied/pasted the code from the api and was still getting the message. Turns out create() is now a static function on the class instead of the object. All this means is you have to access it off of the class GoogleMaps (uppercase) instead of the object googleMaps (lowercase).
The code below should work:
this.map = GoogleMaps.create('canvas', mapOptions);