Merge branch 'ci' into 'master'

add ci pipeline

See merge request !1
2 jobs for master in 10 minutes and 11 seconds (queued for 3 seconds)
Name Stage Failure
failed
auto build and push Build
Successfully tagged johannesloher/d-webservice-example:master
$ docker push $CI_REGISTRY_IMAGE:latest $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG
"docker push" requires exactly 1 argument.
See 'docker push --help'.

Usage: docker push [OPTIONS] NAME[:TAG]

Push an image or a repository to a registry
ERROR: Job failed: exit code 1