The java.io.File methods for creating directories report failure by
returning false. To ease proper checking of return values provide
utility methods wrapping mkdir() and mkdirs() which throw IOException
on failure.
Also fix the tests to store test data under a trash folder and cleanup
after test.
Change-Id: I09c7f9909caf7e25feabda9d31e21ce154e7fcd5
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>