Really fix django-oauth-toolkit version

This is the simplest way to keep all test configurations happy...

ref 85db6c9d79

requirements/testproj.txt

@@ -8,5 +8,5 @@ djangorestframework-camel-case>=0.2.0
 djangorestframework-recursive>=0.1.2
 dj-database-url>=0.4.2
 user_agents>=1.1.0
-django-oauth-toolkit>=1.1.0,<1.2.0; python_version == "2.7"
-django-oauth-toolkit>=1.2.0; python_version >= "3.4"
+# django-oauth-toolkit 1.2 does not support Django 1.11
+django-oauth-toolkit>=1.1.0,<1.2.0