- [socket io multi room chat](http://psitsmike.com/2011/10/node-js-and-socket-io-multiroom-chat-tutorial/)

first time :
	npm install --save express
	npm install --save socket.io
	sudo npm install -g nodemon

next time :
	npm install

anytime :
	nodemon server

- [ ] don't send message to oneself
- [ ] create a room
- [ ] automatically add someone to a room
- [ ] being able to accept or refuse to be added to a room
- [ ] what to do with message not received ?

```
-> create_room('create_room', room_name);
-> change_room('change_room', room_name);
-> get_room_history('get_room_history', room_name);
```