Support more authentication mechanism

[wingyplus]

Currently, the library supports:

• insecure
• SSL/TLS authentication

But here is some missing in the library:

• [ ] ATLS authentication. (Here is Go example: https://grpc.io/docs/languages/go/alts/)
• [ ] Token base authentication. (https://grpc.io/docs/guides/auth/#using-google-token-based-authentication)

The goal is support missing authentication mechanism. I'm not sure how to do it at the moment. Feel free to discuss.

Ref: https://grpc.io/docs/guides/auth/