[ANN] nokogiri 1.6.6.3 Released (security update)

[Mike Dalessio]

nokogiri version 1.6.6.3 has been released!

Changes:

### 1.6.6.3 / 2015-11-16

This version pulls in several upstream patches to the vendored libxml2 and libxslt to address:

* CVE-2015-1819

* CVE-2015-7941_1

* CVE-2015-7941_2

* CVE-2015-7942

* CVE-2015-7942-2

* CVE-2015-8035

* CVE-2015-7995

See #1374 (https://github.com/sparklemotion/nokogiri/issues/1374) for details.