Fix bug with returning jsons

The Requests library changed to switch Response.json is a function instead of an
attribute. Because of this change, errors were being thrown while trying
to access the meta and objects part of the json response.

This change to Requests was made here:
https://github.com/kennethreitz/requests/commit/1451ba0c6d395c41f86da35036fa361c3a41bc90#requests/models.py