add a python websocket proxy which works on Linux, while ws proxy_server does not

test/compatibility/python/websockets/Dockerfile

@@ -0,0 +1,8 @@
+FROM python:3.8.0-alpine3.10
+
+RUN pip install websockets
+COPY ws_proxy.py /usr/bin
+RUN chmod +x /usr/bin/ws_proxy.py
+
+EXPOSE 8765
+CMD ["python", "/usr/bin/ws_proxy.py"]