Remove py26 support

As of mitaka, the infra team won't have the resources available to
reasonably test py26, also the oslo team is dropping py26 support
from their libraries. sine we rely on oslo for a lot of our work,
and depend on infra for our CI, we should drop py26 support too.

Change-Id: I6420a95a58c85830412ae5792208d952116ca7e6
Closes-Bug: 1519510

setup.cfg

@@ -17,7 +17,6 @@ classifier =
     Operating System :: POSIX :: Linux
     Programming Language :: Python
     Programming Language :: Python :: 2
-    Programming Language :: Python :: 2.6
     Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.2

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 1.6
-envlist = py26,py27,py33,py34,pypy,pep8
+envlist = py27,py33,py34,pypy,pep8
 skipsdist = True
 
 [testenv]