message: appveyor: adapt to new unit test exe name
diff: @@ -114,11 +114,11 @@ test_script:
  cp build\libs\gtest\googlemock\gtest\Debug\gtest_maind.dll build\Debug\ &&
  cp build\libs\gtest\googlemock\Debug\gmockd.dll build\Debug\ &&
  cd build\Debug &&
  - unit_tests_runner.exe
  + dronecore-unittests.exe
  ) else (
  cp build\libs\gtest\googlemock\gtest\Release\gtest.dll build\Release\ &&
  cp build\libs\gtest\googlemock\gtest\Release\gtest_main.dll build\Release\ &&
  cp build\libs\gtest\googlemock\Release\gmock.dll build\Release\ &&
  cd build\Release &&
  - unit_tests_runner.exe
  + dronecore-unittests.exe
  )
  