Remove Ponos from CE

Makefile

arkindex/documents/fixtures/data.json

arkindex/ponos/admin.py

arkindex/ponos/api.py

arkindex/ponos/authentication.py

arkindex/ponos/keys.py

arkindex/ponos/management/__init__.py

arkindex/ponos/management/commands/__init__.py

arkindex/ponos/management/commands/generate_private_key.py

arkindex/ponos/migrations/0001_initial.py

arkindex/ponos/models.py

arkindex/ponos/renderers.py

arkindex/ponos/serializers.py

arkindex/ponos/tests/test_admin.py

arkindex/ponos/tests/test_api.py

arkindex/ponos/tests/test_artifacts_api.py

arkindex/ponos/tests/test_keys.py

arkindex/ponos/tests/test_models.py

arkindex/ponos/tests/test_tasks_attribution.py

arkindex/process/builder.py