[system-tests]Add additional output

[Dmitry Tyzhnenko]

We run a lot of tests and we need additional output for improve quality and speed of investigation

Some ideas:
1. Show scenario when run test
2. Mark start and finish scenario step

[Ryan Moe (rmoe)]

Medium priority bugs are not backported to stable releases.

[Dmitry Tyzhnenko (dtyzhnenko)]

https://github.com/stackforge/fuel-qa/blob/master/fuelweb_test/helpers/decorators.py#L62-L64

[Dmitry Tyzhnenko (dtyzhnenko)]

Example output:

2015-03-31 09:49:52,139 - INFO decorators.py:64 --
<<<<<##############################[ deploy_ha_one_controller_flat ]##############################>>>>>
Deploy cluster in HA mode with flat nova-network

        Scenario:
            1. Create cluster in HA mode with 1 controller
            2. Add 1 node with controller role
            3. Add 1 node with compute role
            4. Deploy the cluster
            5. Validate cluster was set up correctly, there are no dead
            services, there are no errors in logs
            6. Verify networks
            7. Verify network configuration on controller
            8. Run OSTF

        Duration 30m
        Snapshot: deploy_ha_one_controller_flat

[Dmitry Tyzhnenko (dtyzhnenko)]

https://github.com/stackforge/fuel-main/blob/master/fuelweb_test/helpers/decorators.py#L60-L62