Check that a pool have a minimum number of workers (#213)

* Check that a pool have at least one worker,

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Specify return type on checkNumberOfWorkers

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Fix dynamic pool handling and add unit tests.

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Add more sanity checks to numberOfWorkers.

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Increase branches coverage.

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Renable skipped test on cluster worker.

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Remove wrong comment.

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Try to increase coverage by alternating fixed pool type.

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Address review comments.

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Sync package-lock.json

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Remove debug log.

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Fix tests (#218)

* Fix the unit test for the number of workers.

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
* Cleanups.

Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
Co-authored-by: Shinigami <chrissi92@hotmail.de>