feat(GoogleMaps): render VirtualContainer as children
feat(GoogleMaps): render VirtualContainer as children

* Fixes #61 and thanks to @idolize
* It seems that <VirtualContainer> can co-exist with the dom created by google.maps.Map.
* Since React use data-reactid to update children of <VirtualContainer>, there's little chance that the children of <GoogleMaps> will be cleared due to diff algorithm.

RishabhJain96/react-google-maps,joshcarr/react-google-maps,jossi87/react-google-maps,tomchentw/react-google-maps,RishabhJain96/react-google-maps,ksavenkov/react-google-maps,jossi87/react-google-maps