Add python 2.6 to tox testing.
diff --git a/tox.ini b/tox.ini
index b7c6591..492de8d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27
+envlist = py26, py27
 
 [testenv]
 deps = keyring
@@ -10,6 +10,7 @@
        webtest
        nose
        uritemplate
+       oauth2client
 setenv = PYTHONPATH=../google_appengine
 
 [testenv:py26]