Sprint 4 system blackbox separate gearslothds

Blackbox tests where instances of gearslothd are used separately. The tests use an sqlite adapter with 100 ms poll_timeout.
* a single instance of all components
** immediate execution
* three instances of all components
** immediate execution
** 6 second delay execution

Tests do not pass locally or on vagrant, probably because a component fails. It seems that a task is sent to multiple bottom level workers when it expires. Perhaps something to do with the adapter not locking the task in time due to the lack of locking?