Provide kwargs from UnitTest to stress test scenarios

[Julien Leloup]

At the moment, stress test implemented with the @stresstest decorator in scenarios scripts can only be configured using the tempest.conf configuration file, mostly withthe [scenario] section.

By launching these stress tests with the "run_stress.py" and providing a JSON configuration file, some parameters can be provided in kwargs but these parameters are only available in the "UnitTest" class.

I think it could be a good thing to transfer these kwargs from the UnitTest setUp() to the scenario implementing the stress test, during the setUpClass() call.

This will allows stress tests scenarios to use configuration from the JSON files instead of bloating the [scenario] section of the tempest.conf

[Andrea Frittoli (andrea-frittoli)]

The stress test framework is not part of Tempest anymore.