Merge pull request #5 from assertible/dependabot/bundler/rack-2.2.4

Bump rack from 2.2.3 to 2.2.4

Author: CodyReichert

Gemfile.lock

@@ -4,7 +4,7 @@ GEM
     json (2.3.0)
     mustermann (1.1.1)
       ruby2_keywords (~> 0.0.1)
-    rack (2.2.3)
+    rack (2.2.4)
     rack-protection (2.2.0)
       rack
     ruby2_keywords (0.0.5)