Update .gitlab/ci/test.gitlab-ci.yml, .gitlab/ci/deploy.gitlab-ci.yml, .gitlab/ci/build.gitlab-ci.yml files

.gitlab/ci/build.gitlab-ci.yml

@@ -7,6 +7,8 @@ build:
     name: multi_user
     paths: 
      - multi_user
-    only:
-     - master
+  only:
+    ref:
+      - master
+
 

.gitlab/ci/deploy.gitlab-ci.yml

@@ -18,4 +18,6 @@ deploy:
     - docker tag registry.gitlab.com/slumber/multi-user/multi-user-server:${VERSION} registry.gitlab.com/slumber/multi-user/multi-user-server:${CI_COMMIT_REF_NAME}
     - docker push registry.gitlab.com/slumber/multi-user/multi-user-server
   only:
-    - master
+    ref:
+      - master
+

.gitlab/ci/test.gitlab-ci.yml

@@ -4,4 +4,5 @@ test:
   script:
     - python3 scripts/test_addon.py
   only:
-    - master
+    ref:
+      - master