v1.3.3 Threads fix, update ephemeral doc

Release 1.3.3 (#130)

* Add some tests, including for ephemeral models

* Fix lint

* Update readme to show ephemeral validated

* Add ephemeral limitation to readme

* Use copy of custom settings to keep new connections clean

* Remove debug client

* Ensure that our unique session id isn't stomped on in custom settings

* Add seed column types to seeds test

* Update docs with limitations and thread info