emitting an event after opening new step

[CedricDsmet]

Hey, i'm using a leaflet map inside one of the steps. when leaflet is initialized the map is hidden, this causes some errors. The solution however is simple, the moment that the map can be seen the map.invalidateSize() function should be run. So i tried to run this function in an eventlistener to the stepopen signal.
The problem however is that this signal is emitted before the animation is ended. I solved the problem by reemitting this signal when the animation is finished and that did the trick. maybe it can be handy to add an extra signal for this, or replace the stepopen signal to that place.
for the rest really nice library thanks a lot 👍

[DavidLibeau]

As far as I know, the events seems to be fired at the wrong moment. For instance, when stepopen is fired the instance.getSteps().active is not the step oppenned but still the previous one. In my opinion, it shouldn't.