Adding auth C++ examples.
Adding auth C++ examples.

Fixes the C++ part of #181.

avx2/avx2.github.io,wildebeestdev/grpc.github.io,avx2/avx2.github.io,wildebeestdev/grpc.github.io,wildebeestdev/grpc.github.io,avx2/avx2.github.io