Log Message:
Update ruby-childprocess to 0.5.8.

pkgsrc change: update HOMEPAGE.

0.5.8

* Merge pull request #94 from portertech/hotfix/windows-jobs
  Fix Windows process job handle leak
* [windows-jobs] fix windows process job handle leak
  this fixes sensu/sensu#1057

0.5.7

* Fix posix_spawn bug when $stdout is overriden
* Add failing test case for $stdout = StringIO
* Fix header
* Add caveat for #89