Add bandit to pep8 job

Add the bandit security scanner to the pep8 job.

Change-Id: I1bd306757a04e6c81b2717c656f71a9e6c9d0d32

test-requirements.txt

@@ -14,3 +14,6 @@ oslotest>=1.10.0 # Apache-2.0
 oslo.i18n>=3.15.3 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
 reno>=2.5.0 # Apache-2.0
+
+# Bandit security code scanner
+bandit>=1.1.0 # Apache-2.0

tox.ini

@@ -11,7 +11,12 @@ deps =
 commands = python setup.py testr --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
-commands = flake8
+deps =
+  -r{toxinidir}/test-requirements.txt
+commands =
+  flake8
+  # Run security linter
+  bandit -r oslo_serialization tests -n5
 
 [testenv:venv]
 commands = {posargs}