Change oioioi~master~I0889402540833dc1de261370217040acbf1609d0, patchset 10
https://gerrit.sio2project.mimuw.edu.pl/3482
SIO-2362 Fix python3 tests.
Fix html-content encoding in testrun.
Fix NoneType comparison in problems/views.py.
Fix dict_type + operation in problems/views.py.
Fix response_body in contests/tests/tests/py.
Fix zeus module.
Fix testspackages (remove name encoding in views).
Fix filetracker storage.py encode str if python3.
Fix mailsubmit (now hashing algorithm is required).
Fix testrun (change bytes to string).
Try fixing printer (checks on hudson).
Change-Id: I0889402540833dc1de261370217040acbf1609d0
(no-ticket) Fix python3 syntax errors
Change-Id: I05a69de42cc5ba467f97f86505c917557a9e5045