add Rakefile into gem

diff --git a/Rakefile b/Rakefile
index 33ef65f..5c434f2 100644 (file)
--- a/Rakefile
+++ b/Rakefile
@@ -43,7 +43,8 @@ end
 
 PKG_FILES = FileList[
   'lib/**/*.rb',
-  'spec/**/*_spec.rb'
+  'spec/**/*_spec.rb',
+  'Rakefile',
 ]
 
 spec = Gem::Specification.new do |s|