Log Message:
Update ruby-mixlib-shellout to 2.2.3.

Release 2.2.3

* Kill all child processes on Windows when a command times out.

Release 2.2.2

* Ship gemspec and Gemfiles to facilate testing.
* Fix #111 by pulling in an updated version of win-32/process and correctly
  patching Process::create.
* Kill all child processes on Windows when a command times out.