Log Message:
textproc/ruby-builder: update to 3.2.4

Update ruby-builder to 3.2.4.

== Version 3.2.3 (2017-01-13)

* Support for Ruby 2.4

== Version 3.2.2 (2013-06-01

* Misc minor fixes

== Version 3.2.1 (2013-05-30)

* Travis & Rdoc fixes

== Version 3.2.0 (2013-02-23)

* Ruby 2.0 compatibility changes.

* Allow single quoted attributes.