Rakefile in d3-rails-3.5.6 vs Rakefile in d3-rails-3.5.11

@@ -1,2 +1,20 @@
 require 'bundler'
 Bundler::GemHelper.install_tasks
+
+namespace :d3 do
+  desc 'Update d3 version'
+  task :update_version do
+    `curl -o app/assets/javascripts/d3.js https://raw.githubusercontent.com/mbostock/d3/master/d3.js`
+    `curl -o app/assets/javascripts/d3.min.js https://raw.githubusercontent.com/mbostock/d3/master/d3.min.js`
+    `cp app/assets/javascripts/d3.js app/assets/javascripts/d3.v3.js`
+    `cp app/assets/javascripts/d3.min.js app/assets/javascripts/d3.v3.min.js`
+    version = `grep 'version: ".*"' app/assets/javascripts/d3.js | cut -d '"' -f 2`.strip
+    message = <<-MSG
+      Please update the version to #{version} manually in the following files:
+      * CHANGELOG.md
+      * README.md
+      * lib/d3/rails/version.rb
+    MSG
+    puts message.strip.squeeze ' '
+  end
+end