Merge pull request #3 from slack-ruby/dependabot/bundler/rack-2.2.3

Bump rack from 2.2.2 to 2.2.3

Author: dblock

Gemfile.lock

@@ -135,7 +135,7 @@ GEM
       racc (~> 1.4)
     public_suffix (4.0.4)
     racc (1.5.2)
-    rack (2.2.2)
+    rack (2.2.3)
     rack-accept (0.4.5)
       rack (>= 0.4)
     rack-cors (1.1.1)