Switching OpenID Connect login to Jetstream 2

Note: this change was already applied to the Jetstream production environment.

How to Test

• Get a Jetstream 2 account from @j.michael.lowe
• Go here https://exosphere.jetstream-cloud.org/exosphere/loginpicker
• Click "Add XSEDE Account"
• Confirm that you can log in

Screenshots

QA Checklist

• Any changes to 'widgets' in src/Style/Widgets/? If so:
  • Update src/Style/StyleGuide.elm showing example usage of that widget
• Were any app flags created, modified, or removed? If so:
  • Update config.js and all files in environment-configs/, including docker-config.js
  • Update "Runtime configuration options" documentation in README.md

Post-Merge Checklist

• Create follow-up issues for anything left over for another merge request
  • If any technical debt is introduced, assign these follow-up issues to the MR submitter