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* Drop support for Django < 1.8
* Add support for Django 1.11.
* Remove `utils.get_all_field_names` and `utils.get_field_by_name` helper methods. See https://docs.djangoproject.com/en/1.10/ref/models/meta/migrating-from-the-old-api for replacements for these methods.
* Update `DummyStorage` to support the `Sequence` protocol instead of the `Iterator` protocol.