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-161
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Cache-Control: max-age=0, no-cache, no-store, must-revalidate
Content-Type: application/json
Expires: Tue, 23 Apr 2019 04:00:16 GMT
Vary: Accept

{
    "count": 35,
    "next": null,
    "previous": null,
    "results": [
        {
            "source": "direct-sharing-161",
            "name": "lineage",
            "usernames": [
                "CameoBlewett14",
                "chelsmoritz92",
                "Sylph",
                "Toasty",
                "simino",
                "jmccrary",
                "jwilliams",
                "cascrogg",
                "Fineline123",
                "cowninja",
                "bdaqueen",
                "MarciajsR",
                "sylko",
                "laurenshearer",
                "Shaoobie",
                "decantrix",
                "RKY68",
                "Maisie",
                "cparker354",
                "titch1969",
                "TilleyFreemanGibbs84",
                "swede_male",
                "bshores",
                "TarjaK",
                "ayjayar",
                "Sabrina1618",
                "keyblademaster88",
                "grantmeadors",
                "datapagan",
                "ereed311",
                "Asuggsnurse",
                "KJBW",
                "Brylonsmom",
                "FLAIMSTER",
                "valgar",
                "M_P",
                "katielorrie",
                "dial203",
                "cbeatnik",
                "redbaybound",
                "kelleymic",
                "Cyndisuzz",
                "boopityboopy",
                "Apriltimms85",
                "Memleigh",
                "CedarForest14",
                "Ironrj",
                "kdgreis",
                "chung",
                "pfinney40",
                "Gufi",
                "Zahar",
                "ashley5886",
                "AmberDawn",
                "angelbread22",
                "mmteal",
                "gedankenstuecke",
                "apriha",
                "madprime",
                "beau",
                "blackbearnh",
                "arvkevi",
                "gsdcomo",
                "Ysearcher",
                "sso465",
                "Jsk1957",
                "WalderC",
                "miqrom",
                "OH1702",
                "perenseta",
                "Abomb00",
                "ericjamesu",
                "McTrimm",
                "badgenes",
                "Finderladi",
                "taximadman",
                "tmi",
                "emruddock",
                "gerard",
                "stephenbrad",
                "mozambiquepaul"
            ]
        }
    ]
}