New ward idea: Trap Ward

Saw that riot was experimenting with new wards on PBE and had a cool idea for a ward.

A trap ward is a stealth object you place down on the map and it triggers when an enemy champion steps on it. It creates an untargetable ward in that place that provides vision for some amount of time. It doesn't work that well defensively but offensively can give vision of their jungle or river objectives as they pass through. Not sure how balanced the concept is though I'm not the best player.