Реализация ExtensionService с учётом long polling операций

Makefile

@@ -50,7 +50,7 @@ lint: install-build-requirements
 	flake8 perxis/
 
 generate: clean-proto install-build-requirements
-	find $(PROTO_FILES_DIR) -name '*.proto' -exec python -m grpc_tools.protoc -I ${PROTO_FILES_DIR} --python_out=$(OUTPUT_FILES_DIR) --grpc_python_out=$(OUTPUT_FILES_DIR) {} +
+	find $(PROTO_FILES_DIR) -name '*.proto' -exec python3 -m grpc_tools.protoc -I${PROTO_FILES_DIR} --python_out=$(OUTPUT_FILES_DIR) --grpc_python_out=$(OUTPUT_FILES_DIR) {} +
 	python fix_imports.py
 
 dist: clean generate