Redis queue improvements

## Option 1: Improve our queue

* Implement the Reliable Queues pattern [https://redis.com/glossary/redis-queue/](https://redis.com/glossary/redis-queue/)
* Write tests to show that Consumer does not stop when it encounters panic when processing tasks. (like http.Server)
* Add audit log when a task is enqueued, a task is dequeued, a task is completed.

## Option 2: Migrate to Celery