Give parabola finite action space (#55)

* Give parabola finite action space

* Add whitespace around * sign

src/seals/diagnostics/parabola.py

@@ -32,7 +32,7 @@ def __init__(self, x_step: float = 0.05, bounds: float = 5):
 
         super().__init__(
             state_space=spaces.Box(low=state_low, high=state_high),
-            action_space=spaces.Box(low=-np.inf, high=np.inf, shape=()),
+            action_space=spaces.Box(low=(-2) * bounds, high=2 * bounds, shape=()),
         )
 
     def terminal(self, state: int, n_actions_taken: int) -> bool: