Django-heroku-connect

* Omit is_deleted field for EmailTemplate objects (70)

* Add support for multi-table inheritance (mti) (65)

* Fix `sf_object_name` check on abstract models (66)
* Add admin actions to ignore and retry failed logs

* Auto-create trigger log tables only when necessary. (62)

* Add context manager to bypass write restrictions to create test data (55)

* Fix ORM representation of built in Heroku Connect fields (59)
* Add check for missing upsert fields on read-write mappings (56)
* Fix Django future compatibility (58)