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-132
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Cache-Control: max-age=0, no-cache, no-store, must-revalidate
Content-Type: application/json
Expires: Wed, 24 Apr 2019 16:44:11 GMT
Vary: Accept

{
    "count": 35,
    "next": null,
    "previous": null,
    "results": [
        {
            "source": "direct-sharing-132",
            "name": "uBiome Upload",
            "usernames": [
                "bernie",
                "dzanab",
                "brick66",
                "grifkami",
                "stephenbrad",
                "CylonKillah",
                "snyddogg",
                "nolanchaffin",
                "monicaaj",
                "Fortin",
                "beau",
                "emeadows317",
                "MCzigler",
                "wolfgang8741",
                "NHWYgEzxASKpL0Aa1NHg",
                "LRRK2_JK",
                "stevenkeating",
                "RebeccaEvansH6a1b3",
                "dnvrdavid",
                "srb115",
                "DanJ",
                "Kiwifulla",
                "gedankenstuecke",
                "vpl",
                "Dyfflinviking",
                "mbpalladino",
                "GranoblasticMan",
                "joey",
                "Sophie444ilun",
                "hey_emme",
                "eveleker",
                "JoshuaJBerk",
                "nnoycemd",
                "amraman",
                "lludo",
                "PolaricEntrophy",
                "genenik",
                "miki",
                "Diana",
                "jacobrosenthal",
                "FLAIMSTER",
                "gcampanella",
                "dalldridge",
                "husamia",
                "davereeck",
                "K8teycat",
                "warriorguy",
                "bgg",
                "Explore360",
                "drd2",
                "mvr33",
                "cyberwks",
                "Koush",
                "vishigondi",
                "Elcharles89",
                "WalderC",
                "bdaqueen",
                "hadrieng",
                "emc2",
                "Teachkidsart",
                "mw_pw",
                "jcrben",
                "mdulaney",
                "dogcopter",
                "alove1006",
                "tinareix3",
                "katewac",
                "Denatonium",
                "moses46",
                "eye144",
                "Ironrj",
                "Johnny9",
                "health11",
                "MisterWu"
            ]
        }
    ]
}