Created by: lchenay
Adding priority queue functionality to Bull.
Priority have been design to process job of higher priority more often than lower priority. It will not process all critical before all hight before all normal... This design choice allow us to save many check and Redis request. But it work like a charm and job with hight priority will be processing significantly faster than other.
It's works like normal queue, except that the add function allow an opts.priority options with one of following value: [low, normal, medium, hight, critical].
Due to current design of Redis connection, this priority queue will increase Redis connection by 5.