Make tox.ini run pep8/hacking checks on bin.

This updates the pep8 hacking checks in our tox.ini file so that
we are also scanning the bin directory for HACKING violations.

Change-Id: I4b010ef4dd799f0afe0fcd56c823a611021e8f60

tox.ini

@@ -26,6 +26,8 @@ deps=pep8==1.2
 commands =
   python tools/hacking.py --ignore=N4,E12,E711,E721 --repeat --show-source \
     --exclude=.venv,.tox,dist,doc,*openstack/common*,*lib/python*,*egg .
+  python tools/hacking.py --ignore=N4,E12,E711,E721 --repeat --show-source \
+    --filename=nova* bin
 
 [testenv:pylint]
 setenv = VIRTUAL_ENV={envdir}