Enable PKI tokens for keystone

This switches from UUID based tokens to PKI tokens. Tokens get signed by
keystone, services can validate the token without having to communicate
with keystone API. This setup is using self signed keystone generated
certs as the certs are only used within the services.

Introduces a new variable, country_code, used when generating keystone's
signing cert.
Merge pull request #691 from blueboxgroup/keystone-pki

Enable PKI tokens for keystone
juno needs moar memories
Merge pull request #698 from blueboxgroup/vagrant_mem

juno needs moar memories
Only create a venv when in jenkins

Jenkins is configured to clean workspaces as a post-build action, so
every new build should be a new venv, nice and clean.
Drop pep8

pep8 and ansible don't mix at this point, so drop it from being tested.