Update README with note on cas ticket issue

README.md

@@ -7,7 +7,9 @@ Patch
 ============
 Supporting UNL's October 2018 move to shib.unl.edu/idp/profile/cas requires CAS tickets longer than 256 chars. Manually patch the rack-cas library to support tickets up to 1024.
  - https://github.com/biola/rack-cas/blob/master/lib/rack-cas/cas_request.rb#L35
- - vendor/bundle/ruby/2.2.0/gems/rack-cas-0.16.0/lib/rack-cas/cas_request.rb
+ - vendor/bundle/ruby/3.0.0/gems/rack-cas-0.16.1/lib/rack-cas/cas_request.rb
+
+This has been fixed as of https://github.com/biola/rack-cas/commit/b6787f521e645ebd703d2749c629e84e419c2777 in 2020 but as of May 2022 there is not a newer release than 0.16.1 that includes the update.
 
 Installation
 ============