Migrate unit tests to JUnit5 ?

[rpelisse]

Reading an article on JUnit5 made me realized that of plumbering in Bugclerk unit testing may be simplified by using some new feature of JUnit 5, such as:

• assertAll, to reduce, for instance, the amount of code testing that the returned list of Candidates matches the expectation
• assertThrows, to simplify test expecting throws
• @RepeatedTest or @nested, to factorize Check tests that are often very prone to cut'n'paste (and a change some value) - this may allow to define a "test template" and then tweak depending on the scenario.
• ParameterResolver may also be a nice way to adress the previous issue

http://junit.org/junit5/docs/current/user-guide/