Add state to VerifyThatTestAreRunOnlyOnceTestSuperClass to avoid false failures when running via sbt.

When HavaRunner tests are executed via SBT, both VerifyThatTestAreRunOnlyOnceSuiteImpl and VerifyThatTestAreRunOnlyOnceTestOneImpl are executed,
resulting in tests running twice, thus failing the java8 assertions here..

This flag prevents that