Merge Naeka work

arkindex/documents/admin.py

arkindex/documents/api/elements.py

arkindex/documents/api/entities.py

arkindex/documents/api/filters.py

arkindex/documents/api/ml.py

arkindex/documents/migrations/0007_auto_20190513_1508.py

arkindex/documents/migrations/0008_auto_20190513_1508.py

arkindex/documents/migrations/0009_auto_20190513_1510.py

arkindex/documents/models.py

arkindex/documents/serializers/light.py

arkindex/documents/serializers/ml.py

arkindex/documents/tests/commands/test_delete_corpus.py

arkindex/documents/tests/test_bulk_classification.py

arkindex/documents/tests/test_classes.py

arkindex/documents/tests/test_corpus.py

arkindex/documents/tests/test_moderation.py

arkindex/project/api_v1.py

arkindex/project/mixins.py

arkindex/project/pagination.py

arkindex/project/settings.py