Activate pep8 check that _ is imported

Remove the specification in tox.ini that _ is a builtin so that
it will no longer assume that _ does not need to be imported.
This helps ensure that the _ from i18n is used.

Activating this check did flag violations and they were fixed
in this patch.

Change-Id: Ia7e4c75b2126a67784683d1c22f0e24bc44113a4

glance_store/common/auth.py

@@ -37,6 +37,7 @@ from six.moves import range
 from six.moves import urllib
 
 from glance_store import exceptions
+from glance_store.i18n import _
 
 
 LOG = logging.getLogger(__name__)

glance_store/common/config.py

@@ -27,6 +27,7 @@ from paste import deploy
 
 from glance.version import version_info as version
 from glance_store.common import utils
+from glance_store.i18n import _
 
 paste_deploy_opts = [
     cfg.StrOpt('flavor',

glance_store/common/utils.py

@@ -28,6 +28,8 @@ except ImportError:
 from oslo_utils import encodeutils
 import six
 
+from glance_store.i18n import _
+
 
 LOG = logging.getLogger(__name__)
 

tox.ini

@@ -32,5 +32,4 @@ commands = {posargs}
 # H404  multi line docstring should start with a summary
 # H405  multi line docstring summary not separated with an empty line
 ignore = H301,H404,H405
-builtins = _
 exclude = .venv,.git,.tox,dist,doc,etc,*glance_store/locale*,*openstack/common*,*lib/python*,*egg,build