tests: Remove ReferenceTest

In preparation for switching to BSD license, remove ReferenceTest which
is copyrighted by Sergey Mashkov whom I've not been able to contact.

Signed-off-by: Pekka Enberg <penberg@kernel.org>
Relicense Jato under the 2-clause BSD license

I have permission to relicense Jato under the 2-clause BSD license from
the following people which covers the whole codebase:

  Tomasz Grabiec <tgrabiec@gmail.com>
  Vegard Nossum <vegard.nossum@gmail.com>
  Johannes Laire <johannes@laire.fi>
  Joonas Reynders <joonas.reynders@iki.fi>
  Jussi Virtanen <jussi.k.virtanen@gmail.com>
  Arthur Huillet <arthur.huillet@free.fr>
  Nikhil Sarda <nikhilsarda.iitkgp@gmail.com>
  Saeed Abdullah <saeed.siam@gmail.com>
  Ankit Laddha <ankit1991laddha@gmail.com>
  Michael Tremel <itrekkie@gmail.com>
  Xerces Rånby <xerxes@zafena.se>
  Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
  Balagopal K S <baluks@gmail.com>
  Ana-Maria Farcasi <farcasia@gmail.com>
  Jim Huang <jserv@0xlab.org>
  Thé Dzierzbicki <theo.dz@gmail.com>

Signed-off-by: Pekka Enberg <penberg@kernel.org>