Gemfile in differentiation-0.2.1 vs Gemfile in differentiation-0.2.2

@@ -1,7 +1,11 @@
 source 'https://rubygems.org'
 
 # Specify your gem's dependencies in differentiation.gemspec
 gemspec
 
+gem "bundler"
+gem "rake"
+gem "test-unit"
+
 gem "simplecov"
 gem "pry"