Return an array where each entry is an object with this form:

{ source: "fitbit", name: "Fitbit", usernames: ["beau", "madprime"] }

GET /api/public-data/members-by-source/?source=direct-sharing-112
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Cache-Control: max-age=0, no-cache, no-store, must-revalidate
Content-Type: application/json
Expires: Thu, 03 Dec 2020 20:30:47 GMT
Vary: Accept

{
    "count": 50,
    "next": null,
    "previous": null,
    "results": [
        {
            "source": "direct-sharing-112",
            "name": "Galileo",
            "usernames": [
                "madprime",
                "beau",
                "padams89",
                "gsdcomo",
                "emeadows317",
                "blackbearnh",
                "Fortin",
                "todrobbins",
                "katja",
                "sprague",
                "dnvrdavid",
                "Einsteinium",
                "phenylalanine",
                "ArloJamesBarnes",
                "gedankenstuecke",
                "ramonimo",
                "carlremi",
                "benc",
                "brianpardy",
                "rexdupont",
                "sayaliphatak",
                "MisterWu",
                "GranoblasticMan",
                "kiraj",
                "taximeow",
                "rocketdog42",
                "pfinney40",
                "jrandymac",
                "maximinio",
                "crazybeardude",
                "stevenrick",
                "nikolay",
                "codyndoan",
                "miqrom",
                "saw2112",
                "laharrin",
                "easkowron",
                "ilanso",
                "monicaaj",
                "alappel",
                "yoyehudi",
                "DemonRaven",
                "ideasonwings",
                "Persefonie",
                "azuredominique",
                "dmaynard",
                "sleight82",
                "Mslogica",
                "azureric",
                "Coding_Lizard",
                "rojoto",
                "Crewest",
                "otoledan",
                "mdulaney",
                "Koush",
                "M_P",
                "Maisie",
                "mw_pw",
                "dodo",
                "Ckova",
                "Pkrobbins22",
                "sajeel",
                "clove1126"
            ]
        }
    ]
}