refactor simple TCP server into pkg

pkg/conn/conn.go

@@ -0,0 +1,33 @@
+package conn
+
+import (
+	"fmt"
+	"net"
+)
+
+const (
+	Port = ":3030"
+	Type = "tcp4"
+)
+
+func StartSimple(handler func(conn net.Conn)) error {
+	l, err := net.Listen(Type, Port)
+	if err != nil {
+		return err
+	}
+	defer l.Close()
+
+	fmt.Println(fmt.Sprintf("Listening on port %s", Port))
+
+	for {
+		c, err := l.Accept()
+		if err != nil {
+			return err
+		}
+		go handler(c)
+		err = c.Close()
+		if err != nil {
+			return err
+		}
+	}
+}