Downgrade to JUnit 4.12
Downgrade to JUnit 4.12

Since it does not appear that JUnit 4.13 will be released before Spring
Framework 5.2 GA, I am reverting back to JUnit 4.12 for the time being.

See gh-22894

spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework