Bump rubocop from 0.52.1 to 0.54.0

Bumps [rubocop](https://github.com/bbatsov/rubocop) from 0.52.1 to 0.54.0.
- [Release notes](https://github.com/bbatsov/rubocop/releases)
- [Changelog](https://github.com/bbatsov/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v0.52.1...v0.54.0)

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -371,8 +371,8 @@ GEM
       activerecord (>= 4.2, < 5.2)
       request_store (~> 1.1)
     parallel (1.12.1)
-    parser (2.4.0.2)
-      ast (~> 2.3)
+    parser (2.5.0.5)
+      ast (~> 2.4.0)
     pdf-core (0.7.0)
     pg (1.0.0)
     poltergeist (1.17.0)
@@ -497,9 +497,9 @@ GEM
     rspec-support (3.7.1)
     rspec_junit_formatter (0.3.0)
       rspec-core (>= 2, < 4, != 2.12.0)
-    rubocop (0.52.1)
+    rubocop (0.54.0)
       parallel (~> 1.10)
-      parser (>= 2.4.0.2, < 3.0)
+      parser (>= 2.5)
       powerpack (~> 0.1)
       rainbow (>= 2.2.2, < 4.0)
       ruby-progressbar (~> 1.7)