Update rubocop requirement from 0.52.1 to 0.68.1

Updates the requirements on [rubocop](https://github.com/rubocop-hq/rubocop) to permit the latest version.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v0.52.1...v0.68.1)

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

Author: dependabot-preview[bot]

Gemfile

@@ -12,7 +12,7 @@ end
 group :test do
   gem "coveralls", require: false
   gem "rspec", "~> 3.7", require: false
-  gem "rubocop", "= 0.65.0", require: false
+  gem "rubocop", "0.68.1", require: false
 end
 
 group :development, :test do