Fix The Nokogiri Warning

One of the most consistent warnings that has been with me through the years has been that Nokogiri was built against a version of libXML that is different than the version that is dynamically loaded. WARNING: Nokogiri was built against LibXML version 2.6.30, but has dynamically loaded 2.9.0 I had most recently, out of frustration, and due to sundry circumstances, resorted to the --use-system-libraries flag in my project’s bundler config just to get shit done.