Fix rubocop issues

config/environments/test.rb

@@ -1,4 +1,6 @@
-require "active_support/core_ext/integer/time"
+# frozen_string_literal: true
+
+require 'active_support/core_ext/integer/time'
 
 # The test environment is used exclusively to run your application's
 # test suite. You never need to work with it otherwise. Remember that
@@ -19,7 +21,7 @@ Rails.application.configure do
   # Configure public file server for tests with Cache-Control for performance.
   config.public_file_server.enabled = true
   config.public_file_server.headers = {
-    "Cache-Control" => "public, max-age=#{1.hour.to_i}"
+    'Cache-Control' => "public, max-age=#{1.hour.to_i}"
   }
 
   # Show full error reports and disable caching.