Update .gitlab-ci.yml to include docker push for development branch

.gitlab-ci.yml

@@ -80,6 +80,7 @@ docker-push:
     stage: release
     only:
       - master
+      - development
     variables:
         REGISTRY_URL: docker.uibk.ac.at:443
         IMAGE_TAG: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG-$CI_COMMIT_SHA