Update to JUnit 5

[DomGarguilo]

This probably could be done in a single PR since there are only a few tests.

[DomGarguilo]

This should probably happen after #33 is completed.

[DomGarguilo]

This actually might need to happen first since the tests extend SharedMiniClusterBase from the accumulo repo which uses JUnit5 so maybe ill convert the tests to JUnit5 first.