achievements leaderboards
method: GET
URL: /management/achievements/leaderboards.json

RETURN:
{
  "page": "leaderboards",
  "user_ranks": [
              {
                    "position": NUMBER,
                    "name": "USER NAME",
                    "thumb_url": "THUMB URL",
                    "points": NUMBER
              }
         ]
}

To delete an achievement:

method: DELETE

URL: /management/achievements/[ACHIEVEMENT_ID].json

RETURN:
{
  status: true/false
}