Add carrierwave migration.

announcement.gemspec

@@ -300,6 +300,21 @@ if bundle_update_flag
     c = YAML.dump(r).sub("---\n",'')
     open("#{env_pwd}/config/mongoid.yml",'w+'){|f| f.write(c)}
   end
+  if !File.exist?("#{env_pwd}/.carrierwave_upgraded")
+    upgrading = File.exist?("#{env_pwd}/.carrierwave_upgrading")
+    File.open("#{env_pwd}/.carrierwave_upgrading", "w") {}
+    uploaders = Dir.chdir(env_pwd){ Dir.glob("app/uploaders/*") }
+    uploaders.each do |uploader|
+      if upgrading
+        bundler_with_clean_env{%x[cd #{env_pwd} && git checkout -- #{uploader}]}
+      end
+      uploader_contents = File.read("#{env_pwd}/#{uploader}")
+      uploader_contents.gsub!(/^[ \t]*require[ \t]+['"]carrierwave\/processing\/mime_types['"][ \t]*$/, '')
+      uploader_contents.gsub!(/^[ \t]*include[ \t]+CarrierWave::MimeTypes[ \t]*$/, '')
+      File.open("#{env_pwd}/#{uploader}", "w"){|f| f.write(uploader_contents)}
+    end
+    File.open("#{env_pwd}/.carrierwave_upgraded", "w") {}
+  end
 end
 # Describe your gem and declare its dependencies:
 Gem::Specification.new do |s|