Minimum reward when success is now 0.1 (#9)

* Minimum reward when success is now 0.1

* Fixed minimum reward when success

gym_minigrid/minigrid.py

@@ -790,7 +790,7 @@ class MiniGridEnv(gym.Env):
         Compute the reward to be given upon success
         """
 
-        return 1 - 0.5 * (self.step_count / self.max_steps)
+        return 1 - 0.9 * (self.step_count / self.max_steps)
 
     def _rand_int(self, low, high):
         """