fixup! Use python_version in requirements files for 2.6-specific stuff.

Author: gsnedders

tox.ini

@@ -8,8 +8,7 @@ deps =
   pytest-expect
   mock
   py26-base: ordereddict
-  py26-optional: -r{toxinidir}/requirements-optional-2.6.txt
-  {py27,py32,py33,py34,py35}-optional: -r{toxinidir}/requirements-optional-cpython.txt
+  {py26,py27,py32,py33,py34,py35}-optional: -r{toxinidir}/requirements-optional-cpython.txt
   {pypy,pypy3}-optional: -r{toxinidir}/requirements-optional.txt
 
 commands =