Publish JUnit XML report

Summary:
This change prepares a JUnit XML report with tests results.

Ref T948.

Reference:

• https://wiki.jenkins-ci.org/display/JENKINS/JUnit+Plugin
• https://phpunit.de/manual/current/en/logging.html#logging.xml

Test Plan: run tests

Reviewers: dereckson

Maniphest Tasks: T948

Differential Revision: https://devcentral.nasqueron.org/D613