Test cases should avoid dynamic non-test-relevant behavior

[gstuer]

Test cases should avoid dynamic non-test-relevant behavior
We should change dynamic expressions like LocalDate.now() in tests to static constants in order to improve the reliability of the tests. Dynamic behavior should only be part of a test, if the test is especially built for such a parametrization.

Originally posted by @gstuer in #79

[larsk21]

see PR_DynamicTestBehaviour

I already removed LocalDate.now(). Is there any other unnecessary use of randomness in our tests?

[larsk21]

@gstuer ?