nanoc.gemspec in nanoc-4.3.5 vs nanoc.gemspec in nanoc-4.3.6

@@ -25,8 +25,9 @@
   s.required_ruby_version = '>= 2.1.0'
 
   s.add_runtime_dependency('cri', '~> 2.3')
   s.add_runtime_dependency('hamster', '~> 3.0')
   s.add_runtime_dependency('ref', '~> 2.0')
+  s.add_runtime_dependency('parallel', '~> 1.9')
 
   s.add_development_dependency('bundler', '>= 1.7.10', '< 2.0')
 end