Gemfile in actionmailer-balancer-1.0.0 vs Gemfile in actionmailer-balancer-1.1.0

@@ -2,10 +2,13 @@
 
 source 'https://rubygems.org'
 
 gemspec
 
-gem 'mail'
-gem 'rake', '~> 13.0'
-gem 'rspec', '~> 3.0'
-gem 'rubocop', '~> 1.21'
-gem 'rubocop-rspec', require: false
+group :development do
+  gem 'mail'
+  gem 'rake', '~> 13.0'
+  gem 'rspec', '~> 3.0'
+  gem 'rubocop', '~> 1.21'
+  gem 'rubocop-rake', require: false
+  gem 'rubocop-rspec', require: false
+end