{'ROLE_NAME': {'BAR': {'download_url': 'XXX'}, 'FOO': {'download_url':
    'XXX'}, 'db_name': 'somedb', 'db_server': 'dbserver.staging.dmz',
    'download_url': 'XXX', 'plugin': {'server_url':
    'http: //lab.staging.corp/server/'}}}
Replace value in JSON file for key which can be nested by n levels