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-193
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Cache-Control: max-age=0, no-cache, no-store, must-revalidate
Content-Type: application/json
Expires: Tue, 07 Apr 2020 14:07:45 GMT
Vary: Accept

{
    "count": 48,
    "next": null,
    "previous": null,
    "results": [
        {
            "source": "direct-sharing-193",
            "name": "Google Fit",
            "usernames": [
                "padams89",
                "gsdcomo",
                "rhondalea",
                "cjb",
                "rory_rocket",
                "wolfgang8741",
                "Thunderbolt8000",
                "BryanGuilliams",
                "coolcole",
                "paulina_duran",
                "roborative",
                "Damien",
                "Taed",
                "Lucas",
                "RhondaMulholland",
                "jeremyroebuck",
                "phenylalanine",
                "ArloJamesBarnes",
                "gedankenstuecke",
                "jongchul",
                "ramonimo",
                "benc",
                "Gikady",
                "trog2",
                "ronaldleemhuis",
                "Dyfflinviking",
                "teh_g",
                "mheffler",
                "Wwyvern",
                "Multicellular",
                "gbathree",
                "pc22",
                "CrewF24",
                "fpataro",
                "sbtoloc",
                "stephenbrad",
                "pfinney40",
                "maximinio",
                "crazybeardude",
                "nikolay",
                "miqrom",
                "HMurphy42",
                "Raphaekg",
                "saw2112",
                "ilanso",
                "amilcar",
                "back_ache",
                "steevesv",
                "Lmarieclemmer",
                "HiImDannyGanz",
                "TamIAM",
                "Lilly",
                "lorenzomoultrie",
                "dmiller67",
                "kmundy",
                "draco_red",
                "kwok",
                "Coding_Lizard",
                "valgar",
                "acompton6761",
                "danlessa",
                "carolinux",
                "the_fittest",
                "Geekfish",
                "paulusm",
                "cowninja",
                "yeltsinxyz",
                "S_liputra",
                "fabianweiss",
                "vgk",
                "carloboros",
                "inacar",
                "davidpc",
                "Fredrik",
                "JKoskinen",
                "Grandfroid",
                "rssfed23",
                "raywang",
                "FrenchJim",
                "lodrial",
                "pundit",
                "investi9ador",
                "bshogeman",
                "LioChan",
                "Bogusteresa",
                "LukeTheLifeHacker",
                "satra",
                "ronswanson"
            ]
        }
    ]
}