Using aiologger in favor of python-json-logger

[diogommartins]

Motivations:

1. Since BarterDude depends on async-worker, BarterDude already depends on aiologger, which means that the change won't add a new dependency. Instead, we'll be removing one!
2. It will give BarterDude an easy performance boost, contributing to it's fully async design! (It's an old post, but a more detailed explanation can be found here)
3. It has a built-in JSON logger, and it's a well documented and pretty straightforward to integrate with the project. Eg.: aiologger usage in asyncworker

Do you guys think that it's ok if I submit a PR with the changes need to use aiologger instead of python-json-logger?

[dmvieira]

Please yes! \o/

[gligneul]

That would be great! As I said, the main problem that we encountered was capturing the logs in tests.