[elevio] analytics.ready is called before window._elev is actually initialized. #325
Description
Elev.io appears to initialize things in several stages, but the key thing is that analytics.ready is called before window._elev.on(event, callback) is set on window._elev. Consequently, it's rather difficult to do much with elev.io aside from setting up some kind of loop that polls for window._elev to actually be ready for use.