[Feature]Add grpc.default_authority option for authorization

[jcai]

Is your feature request related to a problem? Please describe.
Some gRPC server use token to identify the current user in the same service port.

Describe the solution you'd like
add grpc.default_authority option to grpc channel

see:
wechaty/puppet-service#78

[dchaofei]

@jcai 我为 go-wechaty 加了 grpc.default_authority, 我需要怎么测试一下？

[jcai]

在开发者群里面，联系我一下

[jcai]

或者给我你的微信号

[huan]

I'd like to suggest that we should keep the discussion on GitHub as possible as we can because it will let everyone to know what happened so that they will be able to join if they can contribute.

[dchaofei]

向 @jcai 要了个 token, 测试没问题，可以正常使用蔡大提供的 puppet 服务，稍后我将关闭这个 issue

[huan]

Fantastic!

So glad to know that our Go Wechaty is ready to use Puppet Rock Service from @jcai , and appreciate for your contribution @dchaofei !

[jcai]

@dchaofei Thank you very much,If you have any questions about rock service,please let me know!