Use "trigger" keyword for pipeline

Summary

Use "trigger" keyword for pipeline. See #127 (closed).

Focus

Are the variables set correctly?

Test Environment

Look at pipelines and see if they work.

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related issues
• Up-to-date CHANGELOG.md (or not necessary) Not necessary.
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md (or not necessary)
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

For further good practices have a look at our review guidelines.

.gitlab-ci.yml

@@ -65,6 +65,9 @@ unittest:
 # Trigger building of server image and integration tests
 trigger_build:
   stage: deploy
+  inherit:
+    variables:
+      - DEPLOY_REF
   variables:
     # Renaming variables.
     F_BRANCH: $CI_COMMIT_REF_NAME