GitLab

Feat dtt transition

See merge request HFTSoftwareProject/MoDoCoT-Backend!3

closes #1

should be replaced with a cronjob or something, but machine specific,
nothing todo in the backend logic repo

reworked pipeline to suit all branches

This pulls, builds and publishes now for every branch on the repo
Tag used is the branch name

if the commit the pipeline runs matches the format [0-9]+.[0-9]+.[0-9]+
the release stage is run additionally, which pushs the built image
additionally with the tags 'latest' and the tag.

On Jenkins the old Pipeline configurations are disabled and replaced by
a multibranch pipeline configuration

- based on openjdk:11-jre-slim instead of a base system and
    installing java manually
- removed git installation, we use a maven library for this
    no system installed git needed for anything
- removed this damn proxy env vars
    they have nothing to do baked into an docker image!!
- removed junit downloads
    not needed in backend. The testrunners are responsible
    for what they need
- removed setting of a specific profile
    in prod always the default one should be active,
    use a different profile on your dev machine which you
    DO NOT commit