* adding code for calculating time ago in Java for both version 7 and version 8. The code contains pure java and third-party solutions.
* changing name of test classes to contain UnitTest in order to comply with the rules
* changing TimeGranularity.toMillis to abstract method
* [JAVA-1657] core-java-modules JUnit and Maven Surefire Plugin upgrade
* [JAVA-1657] Changed sub modules parents to core-java-modules and core-java-modules to parent-java
* [JAVA-1657] Upgraded JUnit Jupiter version
* [JAVA-1657] Get JUnit 4 dependency transitively