Merge pull request #41 from edx/mrehan/fix-drf-django-filter-versions

Fix drf and django filter versions.

requirements.txt

 ## NOTE: This is not a working req file -- merely a collection for notes.
 django==1.9
-djangorestframework
+djangorestframework==3.6.4
 django-cors-headers
 django-oauth-toolkit==0.11.0
-django-filter
+django-filter==1.0.4
 newrelic
 uwsgi
 pysftp