Add the GRPC /api branch

[jrconlin]

Contile might want to use the api/Client for auth in order to push content to Google Cloud Storage

https://cloud.google.com/storage/docs/reference/libraries

[pjenvey]

How would these api calls be used by contile's cloud storage code? It seems like the cloud_storage crate handles everything already.

I'm still not quite sure what these "api apis" are exactly for, they are labeled as "Service Management API" and also "Service Control API" here