extra.rb in nanoc-4.11.15

- old
+ new

@@ -15,6 +15,7 @@
   Pruner = Nanoc::Core::Pruner
 end
 
 require_relative 'extra/link_collector'
 require_relative 'extra/jruby_nokogiri_warner'
+require_relative 'extra/srcset_parser'
 require_relative 'extra/core_ext'