You need to have mysql server and existing database
Also you need to fill server/config.json file with your data
And get packages from github by go get
github.com/fanliao/go-promise
github.com/jinzhu/gorm
github.com/jinzhu/gorm/dialects/mysql
In first terminal start server
cd ./server
go run ./
In other terminals start clients
go run ./client/ username password