Enforce pep8/pyflakes rule on python codes

This change makes sure that we apply pyflake8 checks on all python
codes to improve its readability.

Note that there are some rules applied for other OpenStack projects,
but not yet turned on, which should be enabled in the future.

Change-Id: Iaf0299983d3a3fe48e3beb8f47bd33c21deb4972

tools/roles-data-generate.py

@@ -42,6 +42,7 @@ def parse_opts(argv):
 
     return opts
 
+
 opts = parse_opts(sys.argv)
 
 roles = collections.OrderedDict.fromkeys(opts.roles)