Implement IU CAS authentication

[jlhardes]

End users can log in to ArcLight to gather search results for personal use. This feature should be limited to IU-only authenticated users via CAS (https://kb.iu.edu/d/bfpq).

Done Looks Like:

• ArcLight Login redirects to IU CAS service
• IU CAS tickets are used to manage authentication and authorization to ArcLight

[jlhardes]

Question: Do we need this login at all? Bookmarking and search history are all that is available with login and that seems potentially unnecessary, especially if it has to be restricted to IU-only. We don't want to not use CAS for authentication because we do not want to be storing passwords at all. Feature parity with our current service does not include this capability to log in or save anything within the web app. And does this issue require IU developers since it is an IU-specific service we would be using? Not sure we have the capacity for this work.

[jhallida]

We do have the ability (if necessary) to create 'affiliate accounts' for Notch8 users so that can have real IU logins. That's not meaning I'm necessarily advocating for this feature though...

[jlhardes]

We decided to turn off login and the bookmark and history feature to get started. Since our current Archives Online doesn't include this we don't need it for feature parity and we don't have a use case here at IU to support it at this point.