[Merge] lp:~fboucault/camera-app/add_flake8_to_unittests into lp:camera-app/staging

[Florian Boucault]

There are additional revisions which have not been approved in review. Please seek review and approval of these new revisions.
-- 
https://code.launchpad.net/~fboucault/camera-app/add_flake8_to_unittests/+merge/287321
Your team Ubuntu Phablet Team is subscribed to branch lp:camera-app/staging.