Merge branch 'migrate-dataimport' into 'master'

arkindex/dataimport/urls.py

arkindex/dataimport/views.py

arkindex/project/api_v1.py

arkindex/templates/dataimport/credentials.html

arkindex/templates/dataimport/failures.html

arkindex/templates/dataimport/files.html

arkindex/templates/dataimport/list.html

arkindex/templates/dataimport/repositories.html

arkindex/templates/dataimport/repository.new.html

arkindex/templates/dataimport/status.html

arkindex/users/api.py

arkindex/users/providers.py

arkindex/users/tests/test_gitlab_oauth.py

arkindex/users/tests/test_providers.py

arkindex/users/views.py