Correct docker push invocation

.gitlab-ci.yml

@@ -18,6 +18,6 @@ build:
 deploy:
   stage: deploy
   script:
-    - docker login --user ${DOCKER_USER} --password ${DOCKER_PASSWORD}
     - docker tag django ${DOCKER_USER}/django
+    - docker login --username ${DOCKER_USER} --password ${DOCKER_PASSWORD}
     - docker push ${DOCKER_USER}/django