[3.5] Fix pytest 4.1 compatibility (#3498) (#3501)
[3.5] Fix pytest 4.1 compatibility (#3498) (#3501)

(cherry picked from commit 67bc3c2b)

Co-authored-by: Andrew Svetlov <78ffb02e053fbf34ac072295d1e547d35762892a@gmail.com>
KeepSafe/aiohttp,KeepSafe/aiohttp,KeepSafe/aiohttp