Feature/create afc group

@NYULibraries/hydra 
Could someone please review this PR and merge it if it looks OK to you?
I would like another set of eyes to look at the code.
Thank you!
Joe

This pull request finishes [#80295342](https://www.pivotaltracker.com/story/show/80295342)  

**Highlights:**
* add examples to test that the `afc_group` is in the list of approved `ArchiveItAccw` `editors`  
* created authorization group `afc_group` and configured membership for various environments  

**General maintenance:**
* cleaned up some whitespace in `oai_dc_http_reader.rb`