Only run CI/CD on master

.gitlab-ci.yml

@@ -5,8 +5,9 @@ before_script:
   - export TERM=xterm-256color
   - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN registry2.24hr.se
 
-build-shell-executor:
+build-images:
   stage: build
   script:
     - make publish
-
+  only:
+    - master