Implement GolemFist

Assets/Battle/BattleParticipant.cs

@@ -31,6 +31,10 @@ public class BattleParticipant
         return this.maxHP;
     }
 
+    public bool IsAlive() {
+        return this.hp > 0;
+    }
+
     public int DealDamage(int damage) {
         int blockedDamage = Math.Min(damage, this.block);
         if (blockedDamage > 0) {
@@ -43,6 +47,10 @@ public class BattleParticipant
     }
 
     public int Heal(int amount) {
+        if (!IsAlive()) {
+            return 0;
+        }
+
         amount = Math.Min(this.maxHP - this.hp, amount);
         this.hp += amount;
         return amount;