Remove python 2.6 support from python-novaclient

Since oslo is removing support for python 2.6, nova
needs to also remove support from clients and libraries.
This commit is to remove support from python-novaclient.

-- Python 2.6 compatibilty code was removed.
-- Python 2.6 was removed as a tox environment, install venv,
and from the classifiers in setup.cfg.
-- Release notes have been updated.

UpgradeImpact

Co-Authored-By: Andrey Kurilin <andr.kurilin@gmail.com>

Change-Id: I3f587ff38d478d075af5fd014e2b4b8416e185d4
Closes-bug: 1518390

novaclient/client.py

@@ -736,10 +736,6 @@ def discover_extensions(version):
 def _discover_via_python_path():
     for (module_loader, name, _ispkg) in pkgutil.iter_modules():
         if name.endswith('_python_novaclient_ext'):
-            if not hasattr(module_loader, 'load_module'):
-                # Python 2.6 compat: actually get an ImpImporter obj
-                module_loader = module_loader.find_module(name)
-
             module = module_loader.load_module(name)
             if hasattr(module, 'extension_name'):
                 name = module.extension_name

releasenotes/notes/remove-py26-support-f31379e86f40d975.yaml

@@ -0,0 +1,3 @@
+---
+upgrade:
+  - Python 2.6 support has been removed from python-novaclient.

setup.cfg

@@ -16,9 +16,10 @@ classifier =
     License :: OSI Approved :: Apache Software License
     Operating System :: OS Independent
     Programming Language :: Python
-    Programming Language :: Python :: 2.6
+    Programming Language :: Python :: 2
     Programming Language :: Python :: 2.7
-    Programming Language :: Python :: 3.3
+    Programming Language :: Python :: 3
+    Programming Language :: Python :: 3.4
 
 [files]
 packages =

tools/install_venv_common.py

@@ -17,7 +17,7 @@
 virtual environments.
 
 Since this script is used to bootstrap a virtualenv from the system's Python
-environment, it should be kept strictly compatible with Python 2.6.
+environment, it should be kept strictly compatible with Python 2.7.
 
 Synced in from openstack-common
 """
@@ -47,8 +47,8 @@ class InstallVenv(object):
         sys.exit(1)
 
     def check_python_version(self):
-        if sys.version_info < (2, 6):
+        if sys.version_info < (2, 7):
-            self.die("Need Python Version >= 2.6")
+            self.die("Need Python Version >= 2.7")
 
     def run_command_with_code(self, cmd, redirect_output=True,
                               check_exit_code=True):

tox.ini

@@ -1,6 +1,6 @@
 # noted to use py34 you need virtualenv >= 1.11.4
 [tox]
-envlist = py26,py27,py33,py34,pypy,pep8,docs
+envlist = py27,py33,py34,pypy,pep8,docs
 minversion = 1.6
 skipsdist = True