Breaking HTTP handlers into groups

This recipe gives advice on how the HTTP handlers could be separated into modules. 

How to do it...

1. Open the console and create the folder chapter11/recipe08.
2. Navigate to the directory.
3. Create the file handlegroups.go with the following content:

        package main

        import (
          "fmt"
          "log"
          "net/http"
        )

         func main() {

           log.Println("Staring server...")
           // Adding to mani Mux
           mainMux := http.NewServeMux()
           mainMux.Handle("/api/",
           http.StripPrefix("/api", restModule()))
           mainMux.Handle("/ui/",
           http.StripPrefix("/ui", uiModule()))

           if err := http.ListenAndServe(":8080", mainMux); err != nil {
             panic(err)
           }

         }

         func restModule() http.Handler {
           // Separate Mux for all REST
           restApi := http.NewServeMux()
           restApi.HandleFunc("/users", func(w http.ResponseWriter...