Bump sinatra from 2.2.0 to 2.2.3 in /tests/integration/test-app

Bumps [sinatra](https://github.com/sinatra/sinatra) from 2.2.0 to 2.2.3.
- [Release notes](https://github.com/sinatra/sinatra/releases)
- [Changelog](https://github.com/sinatra/sinatra/blob/master/CHANGELOG.md)
- [Commits](sinatra/sinatra@v2.2.0...v2.2.3)

---
updated-dependencies:
- dependency-name: sinatra
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

tests/integration/test-app/Gemfile.lock

@@ -32,24 +32,24 @@ GEM
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
     minitest (5.16.2)
-    mustermann (1.1.1)
+    mustermann (2.0.2)
       ruby2_keywords (~> 0.0.1)
     netrc (0.11.0)
     rack (2.2.3.1)
-    rack-protection (2.2.0)
+    rack-protection (2.2.3)
       rack
     rest-client (2.0.2)
       http-cookie (>= 1.0.2, < 2.0)
       mime-types (>= 1.16, < 4.0)
       netrc (~> 0.8)
     ruby2_keywords (0.0.5)
-    sinatra (2.2.0)
-      mustermann (~> 1.0)
+    sinatra (2.2.3)
+      mustermann (~> 2.0)
       rack (~> 2.2)
-      rack-protection (= 2.2.0)
+      rack-protection (= 2.2.3)
       tilt (~> 2.0)
     table_print (1.5.6)
-    tilt (2.0.10)
+    tilt (2.0.11)
     tzinfo (2.0.5)
       concurrent-ruby (~> 1.0)
     unf (0.1.4)