update rails and its dependencies including i18n and nokogiri

for fixing these security issues:

CVE-2013-6415
CVE-2013-4491
CVE-2013-6417
CVE-2013-6416
CVE-2013-4492
CVE-2013-6460
CVE-2013-6461
CVE-2014-0081
CVE-2014-0080
CVE-2013-6414