change db structure, add goroutine connection handling

structures.go

@@ -9,8 +9,10 @@ type User struct {
 	Color            string
 	IsPasswordHashed bool
 }
-
-type AuthConnection struct {
-	connection *websocket.Conn
-	user       User
+type Client struct {
+	conn *websocket.Conn
+	User *User
+}
+
+type ChatGroup struct {
 }