TODOs
Test de la class Messages
Test de la class MessageApp
Access to file system only in MessageApp class

Access to file system is only done in 2 function in MessageApp
Messages() now only takes an object
This object is defined in messages/messages_object.yaml

Update test to fit new signature of Messages(messageObject)
Plus jolis noms pour les fonctions de test
Ne pas charger un object inexistant
TODOs