Merge pull request #696 from IU-Libraries-Joint-Development/essi-2143_update_rack

update bundled rack to 2.2.20

Author: aploshay

Gemfile.lock

@@ -754,7 +754,7 @@ GEM
       rails (>= 5.0, < 6.2)
       rdf
     racc (1.8.1)
-    rack (2.2.19)
+    rack (2.2.20)
     rack-attack (6.7.0)
       rack (>= 1.0, < 4)
     rack-mini-profiler (3.3.1)