Initial PoC with contribution import from Gitlab issues

.dockerignore

config/settings/base.py

config/urls.py

contributions/core/__init__.py

contributions/core/admin.py

contributions/core/migrations/0001_initial.py

contributions/core/migrations/__init__.py

contributions/core/models.py

contributions/sources/gitlab.py

local.yml

pytest.ini

requirements/base.txt

requirements/local.txt

tests/conftest.py

tests/factories.py

tests/test_gitlab.py

tests/test_models.py