Create working CLI test

[tomasr78]

Create a working CLI test in the CliTests file.

[tomasr78]

@paulius-petkus The CLI will be a multiplatform win, Linux and Mac. Keep in mind that writing the tests.

[paulius-petkus]

Tests and updated program.cs working logic is already in main branch.

[paulius-petkus]

Done. I have just updated readme, as we discussed @tomasr78 . But not closing this task yet, not sure if it satisfies all other cretiria.