Pin drf to < 3.7, fixes failing tests

Author: Jacob

setup.py

@@ -10,7 +10,7 @@
         f.read().decode('utf-8')).group(1)))
 
 rest_framework_require = [
-    'djangorestframework>=3.6.3',
+    'djangorestframework>=3.6.3,<3.7.0',
 ]