Go kit developing flow by using truss

評估

1. 決定 project structure
2. 定義標準 error response 格式，http and Grpc

Some Issues

1. In latest Go version 1.17, truss will throw error like: Imported file not found. Because the go package location is changed, no longer storing in $GOPATH/src. but truss is still using that path.

• try using buf to acquire deps.

2. need to modify the api response case json:"Event,omitempty"`

3. need to modify cmd/liveevent/main.go or svc/server.go