Drop gunicorn

[a-musing-moose]

🎯Aim

Remove the dependency on gunicorn

📕Context

With the 0.30.0 release of Uvicorn it has grown the ability to manage multiple workers. Prior to this uvicorn ran as a single process, which was the main reason that we wrapped it with gunicorn. With uvicorn now capable of process management we should consider dropping the extra dependency and try out uvicorn alone.

Whilst the aim is to remove gunicorn - if during testing this turns out to be a poor choice - then we should make sure we install the new uvicorn-worker package as that is now the correct way to get a gunicorn compatible uvicorn worker.

📝Relevant resources/doc's/people

• UVicorn's built in worker management

✅Acceptance Criteria

• Gunicorn is no longer a dependency
• Uvicorn is configured to be the ASGI server, with multiple workers