Testing for CLI commands

[saurabhdaware]

the functions in helper.js are straight forward we can simply write unit tests (Checkout #28 if you're interested in writing unit test for lib/helper.js) but lib/action.js is comparatively complicated to test since it asks for user inputs.

If you know about any way of handling these user inputs through testing do let me know here :D

[saurabhdaware]

working on a library to solve for user inputs in clis https://github.com/saurabhdaware/cli-testing-library