Bump rubocop-rails from 2.6.0 to 2.7.0

Bumps [rubocop-rails](https://github.com/rubocop-hq/rubocop-rails) from 2.6.0 to 2.7.0.
- [Release notes](https://github.com/rubocop-hq/rubocop-rails/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop-rails/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop-rails@v2.6.0...v2.7.0)

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

Gemfile.lock

@@ -150,7 +150,7 @@ GEM
       tilt (>= 1.2)
     hashdiff (1.0.1)
     hashie (4.1.0)
-    i18n (1.8.3)
+    i18n (1.8.4)
       concurrent-ruby (~> 1.0)
     icalendar (2.6.1)
       ice_cube (~> 0.16)
@@ -336,10 +336,10 @@ GEM
       parser (>= 2.7.0.1)
     rubocop-performance (1.7.1)
       rubocop (>= 0.82.0)
-    rubocop-rails (2.6.0)
+    rubocop-rails (2.7.0)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
-      rubocop (>= 0.82.0)
+      rubocop (>= 0.87.0)
     rubocop-rspec (1.42.0)
       rubocop (>= 0.87.0)
     rubocop-thread_safety (0.4.1)