message: Appveyor: Revert copying debug version of DLLs
  CI fails to find debug version of DLLs and hence reverting changes
  to copy release versions of DLLs even in debug configuration.
diff: @@ -113,8 +113,8 @@ test_script:
  copy build\third_party\gtest\googlemock\gtest\Debug\gtestd.dll build\Debug\ &&
  copy build\third_party\gtest\googlemock\gtest\Debug\gtest_maind.dll build\Debug\ &&
  copy build\third_party\gtest\googlemock\Debug\gmockd.dll build\Debug\ &&
  - copy build\plugins\mission\Debug\dronecore_missiond.dll build\Debug\ &&
  - copy build\plugins\mission\third_party\json11\Debug\json11d.dll build\Debug\ &&
  + copy build\plugins\mission\Debug\dronecore_mission.dll build\Debug\ &&
  + copy build\plugins\mission\third_party\json11\Debug\json11.dll build\Debug\ &&
  build\Debug\unit_tests_runner.exe
  ) else (
  copy build\third_party\gtest\googlemock\gtest\Release\gtest.dll build\Release\ &&
  