Integration tests not working in Stash

Integration tests won't work in Stash 2.12.1.

I created a dummy plugin using command atlas-create-stash-plugin. No code or settings were changed. After that I tried to run integration tests on it using atlas-integration-test, but it failed to work properly with such log output: http://pastebin.com/6d1Rywvs

By default the plugin utilize atlassian-plugins-osgi-testrunner version 1.1.4 and the above log file was generated with it.
I was advised to use the newer version of testrunner in which problems with test launch were hopefully solved. So I changed parameter plugin.testrunner.version in POM to 1.2.0 and tried atlas-integration-test again. But I am still unlucky with this log output: http://pastebin.com/Z59ZD4q4

It seems like integration tests are broken from version 2.5.0 of Stash and since Stash source doesn't use them for its testing it remains still unattended.