Add run arguments to results output

[antoniotorresm]

Include the list of arguments for the run to the list of results.

[rcritten]

Test with an authentication test I'm running now. Matches the command-line and produces valid JSON.

[{"source": "ipaperftest.plugins.authenticationtest", "test": "AuthenticationTest", "result": "SUCCESS", "uuid": "7bb04c12-1412-4bbd-8863-8c5df34883de", "when": null, "duration": null, "kw": {"args": ["/home/rcrit/redhat/freeipa-perftest/venv/bin/ipaperftest", "--provider", "idmci", "--test", "AuthenticationTest", "--threads", "1", "--ad-threads", "1", "--amount", "14", "--idmci-lifetime", "6"]}},...

If this is for display and tracking purposes only then it's fine as-is. If we think at some point we might want to programmatically poke at the arguments then that would be difficult in its current form, other than ' '.join(args)

[rcritten]

Antonio confirmed it's only for display. The purpose is to catch as much information on the run as possible.