Report tests results whenever possible
Report tests results whenever possible

Summary: This adjusts the behavior of PytestTestEngine so that it correctly reports test failures natively, rather than throwing a command error.

Test Plan: Yeah right

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D10866

KieranHayes/arcanist,phacility/arcanist,Khan/arcanist,codelabs-ch/arcanist,KieranHayes/arcanist,jra3/arcanist,uber/arcanist,r4nt/arcanist,wxstars/arcanist,kevinseelbach/arcanist,calblueprint/arcanist,Khan/arcanist,jra3/arcanist,alexmv/arcanist,folsom-labs/arcanist,hach-que/arcanist,r4nt/arcanist,haskell-infra/arcanist,phacility/arcanist,coursera/arcanist,Symplicity/arcanist,kevinseelbach/arcanist,codelabs-ch/arcanist,wxstars/arcanist,folsom-labs/arcanist,PageUpPeopleOrg/arcanist-patches,aik099/arcanist,aik099/arcanist,calblueprint/arcanist,memsql/arcanist,chundongwang/arcanist,haskell-infra/arcanist,folsom-labs/arcanist,chundongwang/arcanist,codelabs-ch/arcanist,eSpark/arcanist,memsql/arcanist,memsql/arcanist,phacility/arcanist,hach-que/arcanist,codelabs-ch/arcanist,wharris/arcanist,alexmv/arcanist,haskell-infra/arcanist,Symplicity/arcanist,phacility/arcanist,zhihu/arcanist,wikimedia/phabricator-arcanist,memsql/arcanist,wharris/arcanist,Symplicity/arcanist,fivestars/arcanist,uber/arcanist,r4nt/arcanist,wikimedia/phabricator-arcanist,sneakpeeq/arcanist,PageUpPeopleOrg/arcanist-patches,folsom-labs/arcanist,eSpark/arcanist,uber/arcanist,wikimedia/phabricator-arcanist,wxstars/arcanist,PageUpPeopleOrg/arcanist-patches,calblueprint/arcanist,uber/arcanist,wikimedia/phabricator-arcanist,eSpark/arcanist,KieranHayes/arcanist,fivestars/arcanist,jra3/arcanist,Symplicity/arcanist,Khan/arcanist,jra3/arcanist,PageUpPeopleOrg/arcanist-patches,zhihu/arcanist,aik099/arcanist,wxstars/arcanist,Khan/arcanist,codelabs-ch/arcanist,alexmv/arcanist,r4nt/arcanist,zhihu/arcanist,coursera/arcanist,coursera/arcanist,hach-que/arcanist,eSpark/arcanist,hach-que/arcanist,haskell-infra/arcanist,wharris/arcanist,coursera/arcanist,chundongwang/arcanist,wharris/arcanist,kevinseelbach/arcanist,fivestars/arcanist,KieranHayes/arcanist,kevinseelbach/arcanist,alexmv/arcanist,aik099/arcanist,sneakpeeq/arcanist,phacility/arcanist,calblueprint/arcanist,sneakpeeq/arcanist,zhihu/arcanist,fivestars/arcanist,sneakpeeq/arcanist,chundongwang/arcanist