Revert back to uvicorn

gunicorn creates multiple workers, which is good, but breaks the current
way we're storing results.

Author: pinkwah

backend/Dockerfile

@@ -22,4 +22,4 @@ EXPOSE 8001
 ENV PYTHONDONTWRITEBYTECODE=1
 ENV PYTHONUNBUFFERED=1
 
-CMD ["poetry", "run", "gunicorn", "-b", "0.0.0.0:8000", "-k", "uvicorn.workers.UvicornWorker", "acidwatch_api.app:app"]
+CMD ["poetry", "run", "uvicorn", "acidwatch_api.app:app", "--host", "0.0.0.0", "--port", "8000"]