challenge.py

#!/usr/bin/env python
# -*- coding: UTF-8 -*-

import json
import requests

url = "http://letsrevolutionizetesting.com/challenge"
headers = {'accept': 'application/json'}

while True:

    r = requests.get(url, headers=headers)
    data = r.json()

    if not data.has_key('follow'):
        print data
        break

    url = data['follow']
    print url