added the argparse client.py

[ghost]

Hello, and thank you for your nice contribution (We definitely needed to make the client more self-explanatory)!

Sadly, some tests are not passing since they depend on the old way of testing the client, and your commit message doesn't follow our guidelines. You can amend your commit, and add a commit updating our test suite to cater to your new handling of arguments.

[mh4x0f]

ok, I'll do new commit and fix the travis-ci error. thank