retrieve:
Return the details about the given Memento id.

list:
List all Memento objects.

GET /api/v1/mementos/270/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "id": 270,
    "fr_name": "MechE Colloquium Institut de Génie Mécanique",
    "en_name": "MechE Colloquium Institute of Mechanical Engineering",
    "fr_label": null,
    "en_label": null,
    "slug": "igm-colloquium",
    "is_main_memento": false,
    "is_active": true,
    "memento_url": "https://memento.epfl.ch/igm-colloquium/"
}