Export namespace in ArcanistUnitTestResult dictionary
Summary: D7952 added namespaces to ArcanistUnitTestResult but these are not exported and thus don't get sent from client to server.
Test Plan: Uploaded a diff and inspected the contents of the phabricator_differential.differential_diffproperty table.
Reviewers: epriestley, #blessed_reviewers
Reviewed By: epriestley, #blessed_reviewers
Subscribers: Korvin, epriestley
Differential Revision: https://secure.phabricator.com/D11208