```
$ scripts/install_vddk.py 
Traceback (most recent call last):
  File "scripts/install_vddk.py", line 83, in <module>
    sys.exit(main())
  File "scripts/install_vddk.py", line 34, in main
    filename = args.vddk_url.split('/')[-1]
AttributeError: 'NoneType' object has no attribute 'split'
```

I think this (and address) should be required, and probably positional args. [enable_internal_db.py](https://github.com/RedHatQE/cfme_tests/blob/master/scripts/enable_internal_db.py) has some examples if desired.