in logger/src/main/scala/jetbrains/buildServer/sbtlogger/SbtTeamCityLogger.scala [96:100]
def run(log: Logger, results: Output, taskName: String): Unit = {
//default behaviour there is
//TestResultLogger.SilentWhenNoTests.run(log, results, taskName)
//we will just ignore to prevent appearing of 'exit code 1' when test failed
}