build python version rag-flow (#21)

* clean rust version project

* clean rust version project

* build python version rag-flow

web_server/errors/error_services.py

@@ -0,0 +1,13 @@
+from web_server.errors import FateFlowError
+
+__all__ = ['ServicesError', 'ServiceNotSupported', 'ZooKeeperNotConfigured',
+           'MissingZooKeeperUsernameOrPassword', 'ZooKeeperBackendError']
+
+
+class ServicesError(FateFlowError):
+    message = 'Unknown services error'
+
+
+class ServiceNotSupported(ServicesError):
+    message = 'The service {service_name} is not supported'
+