Task executor

Description

The task executor will fetch tasks from the MongoDB tasks collection and give it to executor workers for execution.

added Backlog label

mentioned in merge request !4 (merged)

changed milestone to %Sprint 6

removed Backlog label

added DevInProgress label

assigned to @lyuben.penkovski

changed milestone to %Sprint 7

mentioned in commit 19ac326f

closed with merge request !4 (merged)