Add flag to mark the window as closed

gym_minigrid/window.py

@@ -90,3 +90,4 @@ class Window:
         """
 
         plt.close()
+        self.closed = True

setup.py

@@ -2,7 +2,7 @@ from setuptools import setup
 
 setup(
     name='gym_minigrid',
-    version='1.0.1',
+    version='1.0.2',
     keywords='memory, environment, agent, rl, openaigym, openai-gym, gym',
     url='https://github.com/maximecb/gym-minigrid',
     description='Minimalistic gridworld package for OpenAI Gym',