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-50
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Cache-Control: max-age=0, no-cache, no-store, must-revalidate
Content-Type: application/json
Expires: Wed, 21 Oct 2020 10:03:10 GMT
Vary: Accept

{
    "count": 50,
    "next": null,
    "previous": null,
    "results": [
        {
            "source": "direct-sharing-50",
            "name": "Gut Instinct",
            "usernames": [
                "beau",
                "jasonbobe",
                "Celia",
                "padams89",
                "jasonhyang",
                "gsdcomo",
                "cct",
                "vbcoach",
                "Mkenned",
                "Chris_Durall",
                "Whynot",
                "annallull",
                "MCzigler",
                "Fortin",
                "Hexaped",
                "yp318041",
                "wolfgang8741",
                "snyddogg",
                "majoshi1",
                "sprague",
                "Sparklingether",
                "phenylalanine",
                "ArloJamesBarnes",
                "gedankenstuecke",
                "Blumounter",
                "MarciajsR",
                "Lms18808",
                "dch",
                "brianpardy",
                "JackieHorne",
                "djhinds",
                "Anothercell",
                "eye144",
                "Gladys60",
                "sidney",
                "johnthomaskennedy",
                "margaretannf",
                "mheffler",
                "kiraj",
                "Winkfield",
                "Sophie444ilun",
                "fpataro",
                "kgelineau",
                "sbtoloc",
                "thelizarmy",
                "rocketdog42",
                "PolaricEntrophy",
                "openhumans12345",
                "stephenbrad",
                "LizMorgan",
                "CherylAnnBachman",
                "aw1231",
                "CHill",
                "brooklyrocks",
                "nikolay",
                "codyndoan",
                "lisaman",
                "VSGlobal",
                "Konvpolto",
                "hkicak",
                "Deniceleon",
                "Gatherer",
                "saw2112",
                "laharrin",
                "gabbycats",
                "Marquian",
                "mutneg",
                "decantrix",
                "Smurf",
                "ROSS",
                "Imey",
                "Whyser",
                "cj27",
                "Winter",
                "easkowron",
                "minaharker",
                "Memoryzine",
                "keithpjolley",
                "Smccart001",
                "Rodin_2000",
                "Shannon_M",
                "generjustin",
                "penny_stock",
                "Kmactx",
                "davereeck",
                "mosaik88",
                "Funsizedfox",
                "dsvoorhees",
                "Arkusinski",
                "SFourie72",
                "vipandey",
                "Crewest"
            ]
        }
    ]
}