Update nokogiri

JonRowe · JonRowe · commit 97451ca16762 · 2018-01-27T22:01:28.000+11:00
diff --git a/Gemfile b/Gemfile
@@ -59,7 +59,7 @@ if RUBY_VERSION < '1.9.2'
 elsif RUBY_VERSION < '1.9.3'
   gem 'nokogiri', '1.5.2'
 else
-  gem 'nokogiri', '1.6.7.1'
+  gem 'nokogiri', '~> 1.8.1'
 end
 
 if RUBY_VERSION <= '1.8.7'
