Use ci configuration from ci repository

.gitlab-ci.yml

-workflow:
-  rules:
-    - if: '$CI_PIPELINE_SOURCE == "merge_request_event"'
-      when: never
-    - when: always
-
-stages:
-  - test
-  - build
-
-Code Quality:
-  stage: test
-  rules:
-    - if: '$CI_PIPELINE_SOURCE == "schedule"'
-      when: never
-    - when: always
-  script:
-    - rm -rf civenv
-    - virtualenv -p python3 --system-site-packages civenv
-    - . ./civenv/bin/activate
-    - pip3 install -I mypy
-    - pip3 install -I git+https://dev.gajim.org/gajim/python-nbxmpp.git@master
-    - pip3 install -I pylint==2.4.4
-    - pip3 install -I codespell
-    - pip3 install -I coverage
-    - pip3 install -I css-parser
-    - pip3 install -I keyring
-    - pip3 install -I packaging
-    - pip3 install -I precis-i18n
-    - pip3 install -I pyOpenSSL
-    - mypy -V
-    - mypy gajim
-    - scripts/ci/pylint.sh --jobs=2 gajim
-    - coverage run --source=gajim -m unittest discover -s test/no_gui -v
-    - coverage report -mi
-    - coverage xml -i
-    - codespell -I codespell.conf --skip="*__pycache__*,gajim/data/icons,gajim/data/sounds,gajim/data/emoticons" gajim
-    - deactivate
-    - rm -rf civenv
-  coverage: "/TOTAL.+ ([0-9]{1,3}%)/"
-  artifacts:
-    reports:
-      cobertura: coverage.xml
-  interruptible: true
-
-appdata.xml:
-  stage: test
-  rules:
-    - if: '$CI_PIPELINE_SOURCE == "schedule"'
-      when: never
-    - when: always
-  script:
-    - python3 setup.py build
-    - appstream-util validate build/data/org.gajim.Gajim.appdata.xml
-  interruptible: true
-
-Linux:
-  stage: build
-  rules:
-    - if: '$CI_PIPELINE_SOURCE == "schedule"'
-      when: never
-    - when: always
-  script:
-    - ./scripts/ci/sdist.py
-
-  artifacts:
-    name: "gajim-$CI_COMMIT_REF_NAME-$CI_COMMIT_SHA"
-    expire_in: 1 week
-    paths:
-      - dist/gajim-*.tar.gz
-  interruptible: true
-
-Windows:
-  stage: build
-  rules:
-    - if: '$CI_PIPELINE_SOURCE == "schedule"'
-  script:
-    - ./scripts/ci/appveyor.py