Gemfile in arbre-1.0.0 vs Gemfile in arbre-1.0.1

@@ -2,9 +2,10 @@
 
 gemspec
 
 group :test do
   gem "rspec"
+  gem "rack"
 end
 
 group :rails do
   gem "rspec-rails"
   gem 'combustion', '0.3.2'