HH-43544 parse text/plain
HH-43544 raise FailedFutureException on Placeholder.get() instead of returning it
Merge remote-tracking branch 'origin/HH-43544' into EXP-11368
release 2.19.16 [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
self.async_group