CPP-616 - Use uv/version.h as version file for libuv v1.21.0+
CPP-616 - Use uv/version.h as version file for libuv v1.21.0+

libuv v1.21.0+ changed where the version file is located.

datastax/cpp-driver,datastax/cpp-driver,datastax/cpp-driver,datastax/cpp-driver