Fix a small bug in Gladstein.

I have tested this locally with axelrod_fortran and this strategy now
agrees with the fortran version against all basic strategies.

Closes #1112

axelrod/strategies/axelrod_second.py

@@ -197,7 +197,7 @@ def strategy(self, opponent: Player) -> Action:
                 return C
             # Cooperate as long as the cooperation ratio is below 0.5
             cooperation_ratio = self.cooperations / len(self.history)
-            if cooperation_ratio >= 0.5:
+            if cooperation_ratio > 0.5:
                 return D
             return C
         else:

axelrod/tests/strategies/test_axelrod_second.py

@@ -138,8 +138,8 @@ def test_strategy(self):
         self.versus_test(axelrod.Alternator(), expected_actions=actions,
                          attrs={'patsy': False})
 
-        # Cooperation ratio will always be less than or equal to 0.5
-        actions = [(D, C), (C, C), (D, C), (C, C), (D, C)]
+        # Cooperation ratio will always be less than 0.5
+        actions = [(D, C), (C, C), (C, C), (D, C), (C, C)]
         self.versus_test(axelrod.Cooperator(), expected_actions=actions,
                          attrs={'patsy': True})
 
@@ -150,6 +150,11 @@ def test_strategy(self):
 
         # Ratio is 1/3 when MockPlayer defected for the first time.
         opponent = axelrod.MockPlayer(actions=[C, C, C, D, D])
-        actions = [(D, C), (C, C), (D, C), (C, D), (C, D)]
+        actions = [(D, C), (C, C), (C, C), (D, D), (C, D)]
+        self.versus_test(opponent, expected_actions=actions,
+                         attrs={'patsy': False})
+
+        opponent = axelrod.AntiTitForTat()
+        actions = [(D, C), (C, C), (C, D), (C, D), (D, D)]
         self.versus_test(opponent, expected_actions=actions,
                          attrs={'patsy': False})