How Do I Auto-Start Teeworlds Server on Ubuntu?

#! /bin/sh -e
# Copyright (c) 2008 Stas Sushkov (stas@nerd.ro)
# Released under GPL 3.0 (http://creativecommons.org/licenses/GPL/2.0/)
# Author: Stas Sushkov, Sept. 2008
### BEGIN INIT INFO
# Provides:          teeworlds-server
# Required-Start:    $network
# Required-Stop:
# Default-Start:   2 3 5
# Default-Stop:      0 1 6
# Short-Description: teeworlds-server daemon, providing teeworlds server administration
# Description:       Teeworlds is an online multi-player plat‐form 2D shooter.
# teeworlds-server is a server for Teeworlds game.
### END INIT INFO

# Used variables
TWSERVER_BIN_DIR=/usr/games
TWSERVER_DIR=/var/games/teeworlds
TWSERVER_CONFIG=teeworlds_srv.cfg
TWSERVER_NAME=teeworlds-server
TWSERVER_OPTS="-q -f $TWSERVER_DIR/$TWSERVER_CONFIG"
TWSERVER_PIDFILE=$TWSERVER_DIR/$TWSERVER_NAME.pid

# Loading init-functions
. /lib/lsb/init-functions

# Check for missing binaries
test -x $TWSERVER_BIN_DIR/$TWSERVER_NAME || { echo "$TWSERVER_BIN_DIR/$TWSERVER_NAME not installed";
        if [ "$1" = "stop" ]; then exit 0;
 else exit 5; fi; }

# Check for existence of needed config file and read it
test -r $TWSERVER_DIR/$TWSERVER_CONFIG || { echo "$TWSERVER_DIR/$TWSERVER_CONFIG not existing";
 if [ "$1" = "stop" ]; then exit 0;
 else exit 6; fi; }

case "$1" in
 start)
  log_begin_msg "Starting Teeworlds Server..."
  umask 002
  if start-stop-daemon -v --start --background \
   --pidfile $TWSERVER_PIDFILE --make-pidfile \
   -d $TWSERVER_DIR \
   --chuid games:games \
   --exec $TWSERVER_BIN_DIR/$TWSERVER_NAME -- $TWSERVER_OPTS; then
   log_end_msg 0
  else
   log_end_msg $?
  fi
 ;;

 stop)
  log_begin_msg "Stopping Teeworlds Server..."
  if start-stop-daemon --stop \
   --pidfile $TWSERVER_PIDFILE; then
   log_end_msg 0
  else
   log_end_msg $?
  fi
 ;;

 restart|force-reload)
  "$0" stop && "$0" start
 ;;

 *)
 echo "Usage: /etc/init.d/teeworlds-server {start|stop|restart}"
  exit 1
 ;;
esac

exit 0