Bump rubocop-rails from 2.21.2 to 2.23.1

Bumps [rubocop-rails](https://github.com/rubocop/rubocop-rails) from 2.21.2 to 2.23.1.
- [Release notes](https://github.com/rubocop/rubocop-rails/releases)
- [Changelog](https://github.com/rubocop/rubocop-rails/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop/rubocop-rails/compare/v2.21.2...v2.23.1)

---
updated-dependencies:
- dependency-name: rubocop-rails
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -547,10 +547,11 @@ GEM
     rubocop-performance (1.19.1)
       rubocop (>= 1.7.0, < 2.0)
       rubocop-ast (>= 0.4.0)
-    rubocop-rails (2.21.2)
+    rubocop-rails (2.23.1)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
       rubocop (>= 1.33.0, < 2.0)
+      rubocop-ast (>= 1.30.0, < 2.0)
     rubocop-rspec (2.27.0)
       rubocop (~> 1.40)
       rubocop-capybara (~> 2.17)
@@ -768,7 +769,7 @@ DEPENDENCIES
   rubocop-capybara (~> 2.20.0)
   rubocop-factory_bot (~> 2.25.1)
   rubocop-performance (~> 1.19.1)
-  rubocop-rails (~> 2.21.2)
+  rubocop-rails (~> 2.23.1)
   rubocop-rspec (~> 2.27.0)
   rvm1-capistrano3 (~> 1.4.0)
   sassc-rails (~> 2.1.2)