The refresehd skin has a submodule "wikifont" in its repo, but the ResourcesTest test are failing because the test infrastructure does not know about this repo and does not clone it for testing.
The configuration needs some fix to let the test pass.
See https://integration.wikimedia.org/ci/job/mwext-testextension-hhvm-composer/9289/console
```
20:22:35 There were 2 failures:
20:22:35
20:22:35 1) Warning
20:22:35 The data provider specified for ResourcesTest::testFileExistence is invalid.
20:22:35 ResourceLoaderFileModule::readStyleFile: style file not found: "/srv/jenkins-workspace/workspace/mwext-testextension-hhvm-composer/src/skins/Refreshed/refreshed/wikifont/wikiglyphs.css"
20:22:35
20:22:35 /srv/jenkins-workspace/workspace/mwext-testextension-hhvm-composer/src/maintenance/doMaintenance.php:111
20:22:35
20:22:35 2) Warning
20:22:35 The data provider specified for ResourcesTest::testStyleMedia is invalid.
20:22:35 ResourceLoaderFileModule::readStyleFile: style file not found: "/srv/jenkins-workspace/workspace/mwext-testextension-hhvm-composer/src/skins/Refreshed/refreshed/wikifont/wikiglyphs.css"
20:22:35
20:22:35 /srv/jenkins-workspace/workspace/mwext-testextension-hhvm-composer/src/maintenance/doMaintenance.php:111
20:22:35
20:22:35 FAILURES!
```