Patch for issue #322

Now that JUnit 4.11 has been released, here's a patch for issue #322. The changes in this patch have been used (against a previous, forked, version of Cucumber-JVM) in our builds for a few months now.

For me, a question mark is whether there is still a need for the DescriptionFactory class, or if that could be deprecated in favour of a straight use of the right Description.createSuiteDescription method from JUnit.