CI jobs for linter and unit testing

.gitlab-ci.yml

+image: registry.git.cccv.de/uffd/docker-images/buster
+
+variables:
+  DEBIAN_FRONTEND: noninteractive 
+  GIT_SUBMODULE_STRATEGY: normal
+  PYLINT_PIN: pylint~=2.10.0
+
+before_script:
+  - python3 -V
+  - lsb_release -a
+  - uname -a
+  - python3 -m pylint --version
+  - python3 -m coverage --version
+
+linter:bullseye:
+  image: registry.git.cccv.de/uffd/docker-images/bullseye
+  stage: test
+  script:
+  - pip3 install $PYLINT_PIN pylint-gitlab pylint-flask-sqlalchemy # this force-updates jinja2 and some other packages!
+  - python3 -m pylint --exit-zero --rcfile .pylintrc --output-format=pylint_gitlab.GitlabCodeClimateReporter 'server.py' > codeclimate.json
+  - python3 -m pylint --exit-zero --rcfile .pylintrc --output-format=pylint_gitlab.GitlabPagesHtmlReporter 'server.py' > pylint.html
+  - python3 -m pylint --rcfile .pylintrc --output-format=text 'server.py' 
+  artifacts:
+    when: always
+    paths:
+    - pylint.html
+    reports:
+      codequality: codeclimate.json
+
+unittests:buster:
+  image: registry.git.cccv.de/uffd/docker-images/buster
+  stage: test
+  script:
+  - python3-coverage run --include 'server.py' -m pytest --junitxml=report.xml || true
+  #- python3-coverage report -m
+  - python3-coverage html
+  #- python3-coverage xml
+  artifacts:
+    when: always
+    paths:
+    - htmlcov/index.html
+    - htmlcov
+    expose_as: 'Coverage Report'
+    reports:
+      #cobertura: coverage.xml
+      junit: report.xml
+  #coverage: '/^TOTAL.*\s+(\d+\%)$/'
+
+unittests:bullseye:
+  image: registry.git.cccv.de/uffd/docker-images/bullseye
+  stage: test
+  script:
+  - python3-coverage run --include 'server.py' -m pytest --junitxml=report.xml || true
+  - python3-coverage report -m
+  - python3-coverage html
+  - python3-coverage xml
+  artifacts:
+    when: always
+    paths:
+    - htmlcov/index.html
+    - htmlcov
+    expose_as: 'Coverage Report'
+    reports:
+      cobertura: coverage.xml
+      junit: report.xml
+  coverage: '/^TOTAL.*\s+(\d+\%)$/'