BUG: Test data was missing since Slicer4 (test was still pointing where data was in Slicer3)

See bug report:
http://na-mic.org/Mantis/view.php?id=3341

The test that was not working does the following:
It runs ResampleDTIVolume and the result of this operation does not matter. What is interesting is that the test makes sure that extending itkTestMainExtended.h to work with DTI did not break the normal behavior of that file and that it still works with scalar images too.
Therefore, it compares a scalar image with itself and verifies that the test passes successfully