changed SpitefulCC classifier and added strategy description

Author: RomeroLaura

axelrod/strategies/grudger.py

@@ -325,7 +325,6 @@ class SpitefulCC(Player):
     classifier = {
         "memory_depth": float("inf"),  # Long memory
         "stochastic": False,
-        "makes_use_of": set(),
         "long_run_time": False,
         "inspects_source": False,
         "manipulates_source": False,
@@ -334,6 +333,10 @@ class SpitefulCC(Player):
 
     @staticmethod
     def strategy(opponent: Player) -> Action:
+        """
+        Cooperates until the oponent defects. Then defects forever.
+        Always cooperates twice at the start.
+        """
         if len(opponent.history) < 2:
             return C
         elif opponent.defections: