Init basic bookshelf server and cli tool

[doi-t]

Still super WIP

Refs:

• https://github.com/campoy/justforfunc/tree/master/30-protobuf
• https://github.com/campoy/justforfunc/tree/master/31-grpc
• https://github.com/campoy/justforfunc/tree/master/32-cobra
• https://github.com/golang-standards/project-layout