Rat Trap fix and change

Hey folks here is a small update!

Fixed:
Rat trap not spawning  rats after being triggered.

Changes:
Stacking Rat Traps will now increase the damage and hp of the spawned rat by 1 for every Rat Trap placed in a room
so 3 rat traps stacked on top of each other will deal 3 damage and then spawn a rat with 3dmg and 3hp after being triggered.
Rat Trap card rarity changed from common->uncommon