message: Add license to gpu csr test file.
diff: +/*******************************<GINKGO LICENSE>******************************
  +Copyright 2017-2018
  +
  +Karlsruhe Institute of Technology
  +Universitat Jaume I
  +University of Tennessee
  +
  +Redistribution and use in source and binary forms, with or without modification,
  +are permitted provided that the following conditions are met:
  +
  +1. Redistributions of source code must retain the above copyright notice,
  + this list of conditions and the following disclaimer.
  +
  +2. Redistributions in binary form must reproduce the above copyright notice,
  + this list of conditions and the following disclaimer in the documentation
  + and/or other materials provided with the distribution.
  +
  +3. Neither the name of the copyright holder nor the names of its contributors
  + may be used to endorse or promote products derived from this software
  + without specific prior written permission.
  +
  +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  +ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  +WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  +DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
  +ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  +(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  +LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  +ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  +SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  +******************************<GINKGO LICENSE>*******************************/
  +
  #include <core/matrix/csr.hpp>
  #include <gtest/gtest.h>
  