ddtrace.gemspec in ddtrace-0.4.0 vs ddtrace.gemspec in ddtrace-0.4.1

@@ -35,6 +35,7 @@
 
   spec.add_development_dependency "rake", "~> 12.0"
   spec.add_development_dependency "rubocop", "~> 0.47"
   spec.add_development_dependency "minitest", "~> 5.10"
   spec.add_development_dependency "appraisal", "~> 2.1"
+  spec.add_development_dependency "yard", "~> 0.9"
 end