Merge pull request #32 from slack-ruby/dependabot/bundler/rack-2.2.3.1

Bump rack from 2.2.3 to 2.2.3.1

Author: dblock

Gemfile.lock

@@ -166,7 +166,7 @@ GEM
       ast (~> 2.4.1)
     public_suffix (4.0.6)
     racc (1.6.0)
-    rack (2.2.3)
+    rack (2.2.3.1)
     rack-accept (0.4.5)
       rack (>= 0.4)
     rack-cors (1.1.1)