(PDK-1464) Update nokogiri due to CVE-2019-5477
(PDK-1464) Update nokogiri due to CVE-2019-5477

This commit updates the minimum nokogiri version to 1.10.4 to mitigate against
CVE-2019-5477.  The PDK package will be updated in a separate commit.

DavidS/pdk,DavidS/pdk,DavidS/pdk