Remove OAuthCredentials, Repository.credentials, Gitlab providers and dependency

README.md

arkindex/documents/fixtures/data.json

arkindex/documents/management/commands/bootstrap.py

arkindex/documents/management/commands/build_fixtures.py

arkindex/documents/management/commands/load_export.py

arkindex/documents/tests/commands/test_load_export.py

arkindex/documents/tests/tasks/test_corpus_delete.py

arkindex/process/admin.py

arkindex/process/api.py

arkindex/process/builder.py

.../process/management/commands/update_repositories_hooks.py

...x/process/management/commands/update_repositories_refs.py

...emove_repository_unique_repository_hook_token_and_more.py

arkindex/process/models.py

arkindex/process/providers.py

arkindex/process/serializers/git.py

arkindex/process/serializers/workers.py

arkindex/process/tests/test_create_process.py

arkindex/process/tests/test_docker_worker_version.py

arkindex/process/tests/test_gitlab_provider.py