XML report output is missing for client tests

[imajus]

Example app

https://github.com/imajus/meteor-browser-tests-issue

Reproduction steps

meteor npm install
meteor npm test

Expected result

Tests must fail for both server and client runs, a folder called test-results must be created and contain exactly two files: server.xml and client.xml.

Actual result

Folder test-results is created but contains only server.xml file, and client.xml is missing.