ClientResponse.release isn't a coroutine

Therefore it should not be one in the MockClientResponse class.

d0af887e31/aiohttp/client_reqrep.py (L832)

vcr/stubs/aiohttp_stubs/__init__.py

@@ -34,7 +34,7 @@ class MockClientResponse(ClientResponse):
     async def read(self):
         return self._body
 
-    async def release(self):
+    def release(self):
         pass