Relax rack dependency

Author: buehmann

rubocop-rails.gemspec

@@ -31,7 +31,9 @@ Gem::Specification.new do |s|
     'bug_tracker_uri' => 'https://github.com/rubocop-hq/rubocop-rails/issues'
   }
 
-  s.add_runtime_dependency 'rack', '>= 2.0'
+  # Rack::Utils::SYMBOL_TO_STATUS_CODE, which is used by HttpStatus cop, was
+  # introduced in rack 1.1
+  s.add_runtime_dependency 'rack', '>= 1.1'
   s.add_runtime_dependency 'rubocop', '>= 0.70.0'
 end
 # rubocop:enable Metrics/BlockLength