Restructuring the tests directory

[rajaswa]

The test cases need to be restructured according to the source directory:

• Separate directory for every subpackage
• Separate file for every module

Check GenRL for reference:
https://github.com/SforAiDl/genrl/tree/master/genrl
https://github.com/SforAiDl/genrl/tree/master/tests

[someshsingh22]

I will take this up,
I think it should be
tests
---- test_module
---- test_package
--------- test_package_module