Make tests run/debug with the new parallelisation code

[gregorgorjanc]

See parallelisation issue at #597 and PR at https://github.com/HighlanderLab/SIMplyBee/pull/609/files/79641ffad46fb45ba5fcbed009c0d781a116ab09..e863ff98cd67b8ca6c2c50d25d68647cf3f2b4c7

[janaobsteter]

The tests now run, implemented in #625