[Development branch] Error in JUnit test in SystematicSampling

[Manuel Luque]

There is an error in JUnit test testSimpleIDWithoutDecisionsDiseaseFourStates in class org.openmarkov.core.model.network.modelUncertainty.SystematicSamplingTest.

Comparing the code with "default" branch, I suspect it may be related to the new potential "ExactDiscretePotential".

[Jorge Pérez]

The class was commented in a previous version. Be noticed that the test are using an old test approach. Adapt these test to the new task approach (or remove them).