Bump rubocop-rspec from 2.17.1 to 2.20.0

Bumps [rubocop-rspec](https://github.com/rubocop/rubocop-rspec) from 2.17.1 to 2.20.0.
- [Release notes](https://github.com/rubocop/rubocop-rspec/releases)
- [Changelog](https://github.com/rubocop/rubocop-rspec/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop-rspec@v2.17.1...v2.20.0)

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

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

Gemfile.lock

@@ -55,13 +55,16 @@ GEM
       unicode-display_width (>= 2.4.0, < 3.0)
     rubocop-ast (1.29.0)
       parser (>= 3.2.1.0)
+    rubocop-capybara (2.18.0)
+      rubocop (~> 1.41)
     rubocop-performance (1.17.1)
       rubocop (>= 1.7.0, < 2.0)
       rubocop-ast (>= 0.4.0)
     rubocop-rake (0.6.0)
       rubocop (~> 1.0)
-    rubocop-rspec (2.17.1)
+    rubocop-rspec (2.20.0)
       rubocop (~> 1.33)
+      rubocop-capybara (~> 2.17)
     ruby-progressbar (1.13.0)
     simplecov (0.22.0)
       docile (~> 1.1)