Merge pull request #26 from cloudfoundry-samples/dependabot/bundler/example_app/rack-2.2.3

Bump rack from 2.0.3 to 2.2.3 in /example_app

Author: elenasharma

example_app/Gemfile.lock

@@ -39,7 +39,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (3.0.0)
-    rack (2.0.3)
+    rack (2.2.3)
     rack-flash3 (1.0.5)
       rack
     rack-protection (2.0.0)