Use random_choice()

Author: janga1997

axelrod/strategies/selfsteem.py

@@ -45,7 +45,7 @@ def strategy(self, opponent: Player) -> Action:
             return opponent.history[-1]
 
         elif sine_value < 0.3 and sine_value > -0.3:
-            return random.choice((C, D))
+            return random_choice()
 
         else:
             return C