Update ruby version to current stable 2.1.4

This release includes security fixes for the following vulnerabilities:

* CVE-2014-8080: Denial of Service XML Expansion
* Changed default settings of ext/openssl related to CVE-2014-3566

And there are some bug-fixes.
Merge pull request #2126 from opf/hotfix/update_ruby_version_for_packager

Update ruby version to current stable 2.1.4