Orc battle at entrance of cave. Player now has hit_points.
Removed additional player_life attribute from n3 tile. It's been moved to Player class.
Support for attack words.
leave method returns True if they manage to flee
Else condition for reporting health is now a catch-all (in case they go into negative hit points).
Fixed leave condition at cave entrance.
Merge pull request #4 from ben174/master

Add new n3 tile with Orc battle at entrance of cave. Player now has hit_points.