Multi-language gRPC prototype.
To generate client's polygon_pb.js
protoc --proto_path=definitions/ --js_out=import_style=commonjs,binary:client/ definitions/polygon.proto
To generate gRPC and golang structs for the server side
protoc --go_out=./server definitions/polygon.proto
protoc -I definitions/ --go_out=plugins=grpc:server definitions/polygon.proto