Update nokogiri per vulnerability report (#1155)
Update nokogiri per vulnerability report (#1155)

Updates nokogiri to 1.6.8.
thoughtbot/hound,platanus/hound,houndci/hound,platanus/hound,thoughtbot/hound,platanus/hound,houndci/hound,thoughtbot/hound,houndci/hound,houndci/hound,thoughtbot/hound,platanus/hound