zdtm.py: add a test name into a progress line

Now it is impossible to find when a test has been started,
but sometimes we want to knwo which tests were running in a specified moment.

travis-ci: success for zdtm.py: add a test name into a progress line
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>