Clean up zombies

self.process.communicate(timeout=0.100) will block

zombies probably would be cleaned up anyways but in a non deterministic fashion by the garage collector

discord/voice_client.py

@@ -124,6 +124,8 @@ class ProcessPlayer(StreamPlayer):
 
     def stop(self):
         self.process.kill()
+        if self.process.poll() is None:
+            self.process.communicate(timeout=0.100)
         super().stop()
 
 class VoiceClient: