Migrate pytest tests to automatically setup local postgres server

[sarahwooders]

We've been using a hosted server for testing, but it'll be easier for contributors to run tests if we automatically setup postgres via #393

[Shoumik-Gandre]

Hello @sarahwooders

Does this mean that when we run pytest, the command should create a docker container that will spin up a postgress database?

If so, I would like to work on it.

[cpacker]

@Shoumik-Gandre check https://github.com/cpacker/MemGPT/tree/main/db for a dockefile