Added Python 3.5 for older Django versions

The versions of DRF for these Django versions should also support Python 3.5.

Author: kevin-brown

tox.ini

@@ -4,8 +4,8 @@ envlist =
        {py27,py34}-django1.8-drf{2.4,3.0,3.1,3.2,3.3,3.4,3.5,3.6}
        {py27,py34}-django1.9-drf{3.3,3.4,3.5,3.6}
        {py27,py34}-django1.10-drf{3.4,3.5,3.6,3.7,3.8}
-       {py27,py34}-django1.11-drf{3.5,3.6,3.7,3.8}
-       {py34}-django2.0-drf{3.7,3.8}
+       {py27,py34,py35}-django1.11-drf{3.5,3.6,3.7,3.8}
+       {py34,py35}-django2.0-drf{3.7,3.8}
        {py35}-django2.1-drf{3.8}
 
 [testenv]