Revert "Don't cache responses"

This reverts commit 5205c05.

Author: osamasayed

app/controllers/application_controller.rb

@@ -39,14 +39,12 @@ def fetch_locale
   end
 
   def set_cache_headers
-    headers['Cache-Control'] = 'no-store, no-cache, max-age=0, private, must-revalidate'
-    headers['Pragma'] = 'no-cache'
-    headers['Expires'] = '0'
-
-    # Keep HSTS header
-    headers['Strict-Transport-Security'] = 'max-age=31536000; includeSubDomains; preload'
+    if action_name != 'random'
+      expires_in 7.day, public: true
+      # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Strict-Transport-Security
+      headers['Strict-Transport-Security'] = 'max-age=31536000; includeSubDomains; preload'
+    end
 
-    # Keep CORS header
     headers['Access-Control-Allow-Origin'] = '*'
   end