Update gitlab references

.gitlab-ci.yml

Dockerfile

Dockerfile.binary

Makefile

README.md

arkindex/dataimport/tests/test_imports.py

arkindex/dataimport/tests/test_transkribus_import.py

arkindex/dataimport/tests/test_workflows_api.py

arkindex/documents/api/elements.py

arkindex/documents/management/commands/bootstrap.py

arkindex/documents/tests/test_children_elements.py

arkindex/documents/tests/test_element_paths_api.py

arkindex/documents/tests/test_metadata.py

arkindex/project/config.py

arkindex/project/tests/config_samples/defaults.yaml

arkindex/project/tests/config_samples/override.yaml

arkindex/users/models.py

requirements.txt