Merge branch 'remove-hidden' into 'master'

arkindex/dataimport/tests/test_workflows_api.py

arkindex/documents/api/iiif.py

arkindex/documents/fixtures/data.json

arkindex/documents/management/commands/build_fixtures.py

arkindex/documents/management/commands/telegraf.py

...ex/documents/migrations/0004_remove_elementtype_hidden.py

arkindex/documents/models.py

arkindex/documents/serializers/iiif/manifests.py

arkindex/documents/serializers/light.py

arkindex/documents/tests/commands/test_telegraf.py

arkindex/documents/tests/test_corpus.py

arkindex/himanis/acts.py

arkindex/himanis/management/commands/import_acts.py

arkindex/himanis/management/commands/import_tei.py

arkindex/himanis/tei.py

arkindex/project/elastic.py

arkindex/project/tests/test_argparse.py

arkindex/project/tests/test_elastic.py