HH-43534 changes for tornado3 upgrade
HH-43534 remove apps option
Merge remote-tracking branch 'origin/HH-43534' into EXP-11489
release 2.19.18 [an.sumin@hh.ru]
new debug with Jinja2
make logging more consistent
new stages, log request_time instead of app total time
improve tests
add tests for debug page
add coverage to tests run
improve frontik.testing
drop python 2.6
add new tests