Finish up flake8 conversion.

Change-Id: I5034f19d5f9b20ad2b4569455273c730b1efec08
diff --git a/tox.ini b/tox.ini
index 85a0d86..4a2f80e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -19,4 +19,9 @@
            python -m tools/tempest_coverage -c report --html
 
 [testenv:pep8]
-commands = bash tools/check_source.sh
+commands = flake8
+
+[flake8]
+ignore = E125,H302,H404
+show-source = True
+exclude = .git,.venv,.tox,dist,doc,openstack,*egg