Depends on Google Maps script before initialization

I am trying to load the Maps script via user-defined API keys so that it requires a delay and locationpicker won't work just because it needs a constant: "google.maps.MapTypeId.ROADMAP" aka "roadmap". 

The example pull-request #107 this kind of issues and removes the initial dependency by keeping the defaults in its main function.
It is just an approach. Any other is quite welcome.