Merge branch 'fix/gitlabci' into 'master'

Update .gitlab-ci.yml

See merge request jonasblatt/ma-jonasblatt-dmn-verifier!16

.gitlab-ci.yml

@@ -51,7 +51,7 @@ verify:jdk8:
   image: maven:3.6.0-jdk-8
 
 deploy:
-  image: busybox:latest
+  image: maven:3.6.0-jdk-8
   stage: deploy
   script:
     - sudo systemctl stop dmn-verifier-backend