Rakefile in stateful_enum-0.2.1 vs Rakefile in stateful_enum-0.3.0

@@ -1,10 +1,19 @@
 require "bundler/gem_tasks"
 require "rake/testtask"
+require 'yaml'
 
 Rake::TestTask.new(:test) do |t|
   t.libs << "test"
   t.libs << "lib"
   t.test_files = FileList['test/**/*_test.rb']
 end
 
 task default: :test
+
+namespace :test do
+  task :all do
+    YAML.load(File.read(File.expand_path('.travis.yml')))['gemfile'].each do |gemfile|
+      sh "BUNDLE_GEMFILE='#{gemfile}' bundle exec rake test"
+    end
+  end
+end