JUnit Jupiter migration completion

[mureinik]

This patch finalizes the upgrade of commons-lang's tests to use JUnit Jupiter and removes the Vintage Engine dependency entirely.

While most of these changes are drop-in replacements with no functional benefit, there are some non-obvious changes worth mentioning.

Unlike org.junit.Assert.assertEquals(double, double, double), org.junit.jupiter.api.Assertions.assertEquals(double, double, double) does not support deltas of zero, only strictly positive deltas.
This issue will be addressed in JUnit Jupiter 5.4 (see junit-team/junit-framework#1613 for details). In the meanwhile, assertTrue(expected==actual) was used, and TODO comments were placed in the code to refactor it to assertEquals once JUnit 5.4 is available.

Unlike org.junit.Test, org.junit.jupiter.api.Test does not have an expected argument. Instead, an explicit call to org.junit.jupiter.api.Assertions.assertThrows is used.

Unlike org.junit.Test, org.junit.jupiter.api.Test does not have a timeout argument either. Instead, an explicit call to org.junit.jupiter.api.Assertions.assertTimeoutPreemptively is used.

JUnit Jupiter also no longer has the concept of Rules. Usages of the SystemDefaultsSwitch rule and its accompanying annotates were replaced with the @DefaultLocale annotation that @britter contributed to JUnit Pioneer, the semi-official JUnit extension project, or simply removed entirely where they had no use (i.e., from StringUtilsEqulasIndexOfTest).
Following the removal of their usages, the @SystemDefaults annotation, the SystemDefaultsSwitch rule and the SystemDefaultsSwitchTest class that tests them had no more use, and they were removed entirely.

It's also worth noting this is a minimal patch for migrating the package's tests to Jupiter. There are several tests that can be made more elegant with Jupiter's new features, but that work is left for subsequent patches.

[coveralls]

Coverage increased (+0.007%) to 95.253% when pulling 8577320 on mureinik:junit-jupiter into ca2e59c on apache:master.

[PascalSchumacher]

Thank you very much for this massive effort! 👍