without cross compiling to linux-musl, optimise image by compiling it on a slim rust image and then transferring only the binary over to a debian-slim image.
Update mail_app to also have different forms of configuration outside of a single base yaml file. Allows local or production configurations to be established.
Logs in much greater detail using the tracing packages and formatted using Bunyan. Advised to install bunyan on machine for more pretty logs over raw json.
Also updated tests to reflect the new PgPool format being used. Tests now create a mock database on creation to determine if it works before removing it. Up to Chapter 4.
