Gemfile in fast_excel-0.4.0 vs Gemfile in fast_excel-0.4.1

@@ -1,18 +1,19 @@
 source 'https://rubygems.org'
 
-gem 'ffi'
-gem 'ffi_gen', require: false
+gemspec
 
 gem 'rake'
 
 gem 'roo', '2.8.3', git: 'https://github.com/roo-rb/roo.git', tag: 'v2.8.3'
 
 gem 'minitest'
 gem 'minitest-reporters'
 
-# For benchmakrs
-gem 'axlsx', git: 'https://github.com/randym/axlsx.git'
-gem 'write_xlsx'
-gem 'xlsxtream'
-gem 'benchmark-ips'
-gem 'process_memory', git: 'https://github.com/paxa/process_memory', platforms: :ruby
+
+group :benchmarks do
+  gem 'axlsx', git: 'https://github.com/randym/axlsx.git'
+  gem 'write_xlsx'
+  gem 'xlsxtream'
+  gem 'benchmark-ips'
+  gem 'process_memory', git: 'https://github.com/paxa/process_memory', platforms: :ruby
+end