Merge pull request #1245 from alphagov/dependabot/bundler/rack-cache-1.16.0

Bump rack-cache from 1.15.0 to 1.16.0

Author: callumknights

Gemfile.lock

@@ -489,7 +489,7 @@ GEM
       nio4r (~> 2.0)
     racc (1.7.3)
     rack (2.2.8.1)
-    rack-cache (1.15.0)
+    rack-cache (1.16.0)
       rack (>= 0.4)
     rack-protection (3.2.0)
       base64 (>= 0.1.0)