The ArcanistPhpunitTestResultParser has been changed
to use phutil_json_decode instead of json_decode in
rARCa4d33ef117aa8702181154b60ce1ce52bcfc119b
That has broken the functionality as json_decode has returned
an object before but phutil_json_decode does return an array.
The code has now been adopted to work with the array result
instead of an object.

Run a phpunit test case