Update pytest to 5.3.0 (#12915)
Update pytest to 5.3.0 (#12915)

Update pytest to 5.3.0
mozilla/addons-server,wagnerand/addons-server,diox/olympia,diox/olympia,mozilla/olympia,mozilla/addons-server,bqbn/addons-server,eviljeff/olympia,mozilla/addons-server,bqbn/addons-server,diox/olympia,bqbn/addons-server,mozilla/addons-server,diox/olympia,wagnerand/addons-server,wagnerand/addons-server,mozilla/olympia,bqbn/addons-server,wagnerand/addons-server,mozilla/olympia,mozilla/olympia,eviljeff/olympia,eviljeff/olympia,eviljeff/olympia