Update Makefile

Author: rllin

Makefile

@@ -13,5 +13,5 @@ test-prod: build
 	docker run -it -v ${PWD}:/usr/src -w /usr/src \
 		-e LABELBOX_TEST_ENVIRON="prod" \
 		-e LABELBOX_TEST_ENDPOINT="https://api.labelbox.com/graphql" \
-		-e LABELBOX_TEST_API_KEY="<REPLACE>"
+		-e LABELBOX_TEST_API_KEY="<REPLACE>" \
 		local/labelbox-python:test pytest $(PATH_TO_TEST)