/conversations/:conversationId/messages/:messageId

{
  id: "117bdasjasd9mj29jd233",
  type: "text/plain",
  body: "hola mundo!",
	sender: {
    id: "1234",
    type : "robot",
    name: null
  },
	conversationId:"asd8bqwwdyqdqydqyasdas",
  sentAt: "2014-09-09T04:44:47+00:00",
  isUnread: true, //depende del user que esté consultando la API
  recipient_status: { //WIP
    "777": "sent",
    "111": "delivered",
    "999": "read",
    "1234": "read"
  }
}

{
  type: "message/http",
  body: "http://www.cliengo.com/precios",
  ...
}

{
  type: "audio/mpeg",
  body: "http://www.cliengo.com/blaasdadadasd.mp3",
  ...
}

{
  type: "email",
  body: "hola esto vino en un email!",
  ...
}