Adding tox support for bandit

Bandit is a code linter which is used to help identify potential
security vulnerabilities. As part of the plan to integrate bandit
into each OpenStack project, support for a tox testenv is step one.
Later, gate tests will also be incorporated.

Change-Id: Ib6ef0a3e8f32f2724314c166d7de50d591c0e949

test-requirements.txt

@@ -3,6 +3,7 @@
 # process, which may cause wedges in the gate later.
 hacking<0.11,>=0.10.0
 
+bandit>=0.17.3 # Apache-2.0
 coverage>=3.6 # Apache-2.0
 discover # BSD
 fixtures>=1.3.1 # Apache-2.0/BSD

tox.ini

@@ -23,6 +23,9 @@ commands =
 [testenv:pep8]
 commands = flake8 {posargs}
 
+[testenv:bandit]
+commands = bandit -r novaclient -n5 -x tests
+
 [testenv:venv]
 commands = {posargs}