Merge branch 'error-report' into 'master'

.gitlab-ci.yml

Makefile

arkindex/dataimport/api.py

arkindex/dataimport/migrations/0003_dataimportfailure.py

arkindex/dataimport/models.py

arkindex/dataimport/serializers.py

arkindex/dataimport/tasks.py

arkindex/dataimport/tests/test_imports.py

arkindex/dataimport/urls.py

arkindex/dataimport/views.py

arkindex/documents/serializers/elements.py

arkindex/documents/serializers/light.py

arkindex/documents/tei.py

arkindex/documents/tests/test_tasks.py

arkindex/documents/tests/test_tei.py

arkindex/project/api_v1.py

arkindex/project/tests/__init__.py

arkindex/project/tools.py

arkindex/templates/dataimport/failures.html