Make the port configurable

config.go

@@ -1,6 +1,7 @@
 package main
 
 const (
+	PORT              = ":8080"
 	DB_IP             = "127.0.0.1"
 	DB_NAME           = "trantor"
 	BOOKS_COLL        = "books"

trantor.go

@@ -154,5 +154,5 @@ func main() {
 	fileHandler("/css/")
 	fileHandler("/js/")
 	http.HandleFunc("/", indexHandler(coll))
-	http.ListenAndServe(":8080", nil)
+	http.ListenAndServe(PORT, nil)
 }