Create API that responds for incoming requests about the registered RFIDs

[danielSbastos]

The RPi server at the Fab Lab will perform requests for this server with the aim of getting back the list of users and theirs rfids present in the DB. We need to create an API for a GET request.

There is an endpoint called /rsids. This is the one that the RPi will make the GET request. We need to respond with something like the following JSON structure:

{
   "rfids": [
      {
         "rfid": 1,
         "deleted_at": null
       },
      {
        "rfid": 2,
        "deleted_at": "Mon Apr 23 2018 12:19:49 GMT-0300 (-03)"
      }
   ]
}

[danielSbastos]

#7