possibility to remove worker

Add a possibility to remove worker.

Not from db but to mark him as removed so he will not appear in all places.

changed milestone to %v.0.10.0

assigned to @piotr.gawron

created branch 151-possibility-to-remove-worker

mentioned in merge request !84 (merged)

closed via commit 4793ed6f

closed via merge request !84 (merged)

mentioned in commit 4793ed6f