Test refactoring (#2427)

* Move tests to root with automatic PyCharm import refactoring. This will likely fail some tests

* Changed entry point for a registration test env.

* Move a stray lunar_lander test to tests/envs/...

* black

* Change the version from which importlib_metadata is replaced with importlib.metadata. Also requiring installing importlib_metadata for python 3.8 now.

???????????

* Undo last commit

tests/vector/test_vector_env_wrapper.py

@@ -0,0 +1,20 @@
+import gym
+from gym.vector import make
+from gym.vector import VectorEnvWrapper
+
+
+class DummyWrapper(VectorEnvWrapper):
+    def __init__(self, env):
+        self.env = env
+        self.counter = 0
+
+    def reset_async(self):
+        super().reset_async()
+        self.counter += 1
+
+
+def test_vector_env_wrapper_inheritance():
+    env = make("FrozenLake-v1", asynchronous=False)
+    wrapped = DummyWrapper(env)
+    wrapped.reset()
+    assert wrapped.counter == 1