Fix CI linting (#273)

.github/workflows/ci.yml

@@ -25,8 +25,11 @@ jobs:
 
       - name: Rubocop
         run: |
-          gem install rubocop rubocop-packaging rubocop-performance --no-document
-          rubocop --format progress
+          gem install bundler
+          bundle config set without 'development test'
+          bundle config set with 'lint'
+          bundle install
+          bundle exec rubocop --format progress
 
       - name: Yard-Junk
         run: |

Gemfile

@@ -2,25 +2,30 @@
 
 source 'https://rubygems.org'
 
-gem 'brotli', '>= 0.1.8', platforms: :mri
-gem 'hashie', '>= 1.2'
-gem 'json', '< 3'
-gem 'multi_xml', '>= 0.5.3'
-gem 'rack', '< 2'
-gem 'rack-cache', '>= 1.1', '< 1.3'
-gem 'rake', '>= 12.3.3'
-gem 'rash_alt', '>= 0.4.3'
-gem 'safe_yaml'
-gem 'simple_oauth', '>= 0.1', '< 0.3'
+group :development do
+  gem 'brotli', '>= 0.1.8', platforms: :mri
+  gem 'hashie', '>= 1.2'
+  gem 'json', '< 3'
+  gem 'multi_xml', '>= 0.5.3'
+  gem 'rack', '< 2'
+  gem 'rack-cache', '>= 1.1', '< 1.3'
+  gem 'rake', '>= 12.3.3'
+  gem 'rash_alt', '>= 0.4.3'
+  gem 'safe_yaml'
+  gem 'simple_oauth', '>= 0.1', '< 0.3'
+end
 
 group :test do
   gem 'addressable', '< 2.4'
   gem 'rspec', '>= 3'
+  gem 'simplecov', '~> 0.12.0'
+  gem 'webmock', '~> 2.3'
+end
+
+group :lint do
   gem 'rubocop', '~> 1.12.0'
   gem 'rubocop-packaging', '~> 0.4'
   gem 'rubocop-performance', '~> 1.5.2'
-  gem 'simplecov', '~> 0.12.0'
-  gem 'webmock', '~> 2.3'
 end
 
 gemspec