Switch to flake8 from pep8.

* flake8 supports more checks than pep8 (e.g. detection of
   unused imports and variables), and has an extension mechanism.
   A plugin to support automatic HACKING validation is planned.
 * See: http://flake8.readthedocs.org/

Change-Id: I8c9314c606802109a4d01908dbc74ecb792ad0ac

tools/test-requires

@@ -4,13 +4,13 @@ coverage>=3.6
 discover
 distribute>=0.6.24
 fixtures>=0.3.12
+flake8
 mock>=1.0b1
 mox==0.5.3
 nose
 nosehtmloutput
 nosexcover
 openstack.nose_plugin
-pep8==1.3.3
 python-subunit
 sphinx>=1.1.2
 testrepository>=0.0.13

tox.ini

@@ -21,13 +21,8 @@ sitepackages = True
 downloadcache = ~/cache/pip
 
 [testenv:pep8]
-# E711/E712 comparison to False should be 'if cond is False:' or 'if not cond:'
-#        query = query.filter(Component.disabled == False)
-# E125 continuation line does not distinguish itself from next logical line
-
 commands =
-  pep8 --repeat --show-source --ignore=E125,E711,E712 --exclude=.venv,.tox,dist,doc,openstack,*egg .
-  pep8 --repeat --show-source --ignore=E125 --filename=quantum* bin
+  flake8
 
 [testenv:i18n]
 commands = python ./tools/check_i18n.py ./quantum ./tools/i18n_cfg.py
@@ -38,3 +33,13 @@ setenv = VIRTUAL_ENV={envdir}
 
 [testenv:venv]
 commands = {posargs}
+
+[flake8]
+# E711/E712 comparison to False should be 'if cond is False:' or 'if not cond:'
+#        query = query.filter(Component.disabled == False)
+# E125 continuation line does not distinguish itself from next logical line
+# H hacking.py - automatic checks of rules in HACKING.rst
+ignore = E711,E712,E125,H
+show-source = true
+builtins = _
+exclude=.venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,tools