First Boss + Fixes!

Hello ev'ryone!

In this update you'll finally meet your first (mini)boss at level 10, an old man that throws boulders at you!
I modelled the system for future bosses as well, so in the next patch you should see some more of them.

I've also fixed that ugly bug that, in blocked-exits rooms made the exit spawn on the last enemy. Now it replaces the blocked exit.

Dev plans are to have at least 3 meaningful bosses (improving this first one as well), then to add trinket and consumables to insert some form of strategy in this pure RNG game. I like the minimal combat system, and I'm happy with a game that doesn't require skill at all, but some build personalisation element are surely to come.

As always, any feedback is appreciated!