Unify testing structure/tools [JSTEP-10]

[JooHyukKim]

This issue serves as an umbrella issue for resolving [JSTEP-10: Unifying testing structure/tools]

TODO

• Add JUnit 5 dep + failing test utils
  • [JSTEP-10] Set-up part (JUnit5 dep & testutil) #703
• Migrate tests to JUnit 5
  • [JSTEP-10] Migrate to JUnit 5 of part 1 #704
  • [JSTEP-10] Migrate to JUnit 5 of part 2 #705
• Migrate failing tests to /tofix and remove existing /failing funciontality
• Remove JUnit 4
  • Remove JUnit4 dependency #706
  • AsPropertyTypeDeserializer._deserializeTypedForId loses FromXmlParser class definition for "jp" #70

[cowtowncoder]

Almost there: I think migrating "failing" to "tofix" is the only thing missing here. Right @JooHyukKim ?