WIP for integrating the lizard sso client.

The sso client will be integrated via the rest api.
Merge branch 'master' into sso-auth

Conflicts:
	ddsc_site/urls.py
WIP: SSO integration via the API.

- CORS headers need to be set correctly.
Add logout functionality in the api.
Add production and staging settings for sso auth.
Merge pull request #2 from ddsc/sso-auth

Integrate API with Lizard SSO.