replace gradle release task by pyb publish_release in gitlab ci

.gitlab-ci.yml

@@ -121,7 +121,7 @@ release-to-meissa:
   stage: release
   allow_failure: true
   script:
-    - ./gradlew createReleaseAndUploadAssets
+    - pyb publish_release
 
 
 after_script:

build.py

@@ -93,7 +93,8 @@ def package(project):
 
 
 @task
-def publish_artifacts(project):
+def publish_release(project):
+    """ creates a release in repo.meissa and uploads artifacts (jar-files and checksum files) """
     build = get_devops_build(project)
     build.publish_artifacts()