Rakefile in protector-0.0.2 vs Rakefile in protector-0.0.4

@@ -1,8 +1,13 @@
 require 'bundler/setup'
 require 'bundler/gem_tasks'
 require 'rspec/core/rake_task'
+require 'appraisal'
 
 RSpec::Core::RakeTask.new(:spec)
 
-desc "Default: run the unit tests."
-task :default => :spec
\ No newline at end of file
+task :default => :all
+
+desc 'Test the plugin under all supported Rails versions.'
+task :all => ["appraisal:install"] do |t|
+  exec('rake appraisal spec')
+end