add oj-backend health check

deploy/health_check.py

@@ -0,0 +1,11 @@
+import xmlrpclib
+
+if __name__ == "__main__":
+    try:
+        server = xmlrpclib.Server('http://localhost:9005/RPC2')
+        info = server.supervisor.getAllProcessInfo()
+        error_states = list(filter(lambda x: x["state"] != 20, info))
+        exit(len(error_states))
+    except Exception as e:
+        print(e.with_traceback())
+        exit(1)