Protean

------------------

* Introduce support for Postgresql Array and JSON columns
* Allow restricting `List` datatype to specific content types

------------------

* Log Protean exceptions to print helpful debug messages
* Support for installation of optional dependencies
* Remove support for Data Transfer Object
* Remove support for Request and Response Objects
* Bugfix - Throw Exceptions on Unit of Work commit failures
* Use `black` as code formatter, with a git pre-commit hook
* Add 3.9 to test matrix and cleanup Travis yml
* Bugfix - Fix broken Sphinx docs build

------------------

* Bugfix 304 - Remove shadow object linkages with aggregates
* Raise InvalidDataError on invalid attributes to Commands
* Treat meta attributes like auto_fields and mandatory_fields as dicts instead of tuples
* Add support for nested serializers/schemas with Marshmallow
* Bugfix to not link shadow fields with Aggregate/Entity classes directly
* Bugfix to set initialize Shadow (Reference) and Value Object attributes correctly
* Store Reference and Value Object fields in `Entity.meta_` for later use
* Allow Subscribers and Handlers to hook into multiple Events
* Bugfix to avoid fetching child records without foreign key linkages
* Add support for Dict serialization
* Allow persisting and management of child entities via the Aggregate object
* Add support for using Celery as the background worker

------------------

* Add support for referencing embedded fields with a defined name
* Fix to allow `default=False` on Boolean fields and subsequent filtering for `False` in field values
* Fix to use Entity attributes to derive field names of unique fields, instead of `declared_fields`
* Add support for logging events into a universal `EventLog` table before publishing to brokers
* Add support for custom models associated with Aggregates/Entities
* Use Elasticsearch specific List and Dict attributes to reconstruct entity
* Bugfix - Verify that ValueField object is not empty before trying to access its attributes
* Bugfix - Fix how Elasticsearch connection is fetched while resetting data

------------------

* Email Notifications Functionality
* Support for SendGrid
* Allow ad-hoc Identity Generation

------------------

* Auto-traversal bug fixes