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: I66d168ecc755a3ea0e01d5b6344d06d9e0d1378b
Closes-Bug: 1519510

Author: Steve Martinelli

setup.cfg

@@ -15,7 +15,6 @@ classifier =
     Programming Language :: Python
     Programming Language :: Python :: 2
     Programming Language :: Python :: 2.7
-    Programming Language :: Python :: 2.6
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.4
 

tox.ini

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