Can't build because cmake option MSGPACK_BUILD_TESTS is now on by default

[T5100]

This line:
OPTION (MSGPACK_BUILD_TESTS "Build msgpack tests." ON)
from this commit
2f54392

caused this error message

CMake Error at /usr/share/cmake-3.16/Modules/FindPackageHandleStandardArgs.cmake:146 (message):
Could NOT find GTest (missing: GTEST_LIBRARY GTEST_INCLUDE_DIR

Because I don't have google test.

Expected behavior
OPTION (MSGPACK_BUILD_TESTS "Build msgpack tests." OFF)

[redboltz]

Thank you for reporting the issue.
I think that the expected behavior you mantioned is right. Could you post the PR to fix it ?

[redboltz]

Fixed by #1069