Warning when using google.maps.MVCArray in Polyline path #25

The MVCArray totally works when it renders, but it just pops up an annoying warning to the console. And more importantly, it lets me add LatLngs to the MVCArray async'ly.

Warning: Invalid prop `path` of type `object` supplied to `Polyline`, expected `array`. Check the render method of `ReactFrag`.

This is an issue of the frag being too tight in PropTypes?