Add JUnit tests in the project

[sumityadav6541]

a gradle build project without unit tests seems very error-prone and buggy.
If you want i can add unit tests in your project !

[grsubramanian]

Sure. Indeed, I am not that great with Gradle. Why don't you do a good reorg of code in this project so that it fits the state of the art Gradle standards. I am adding you as a contributor.

And +1 for noting that unit tests are very important. I wrote this mostly as supporting material for a talk I gave at ThoughtWorks on design patterns.

Thanks and cheers.