async.gemspec in async-1.10.3 vs async.gemspec in async-1.11.0

@@ -17,11 +17,10 @@
 
 	spec.files         = `git ls-files`.split($/)
 	spec.executables   = spec.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
 	spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
 	spec.require_paths = ["lib"]
-	spec.has_rdoc      = "yard"
-	
+
 	spec.required_ruby_version = ">= 2.2.7"
 
 	spec.add_runtime_dependency "nio4r", "~> 2.3"
 	spec.add_runtime_dependency "timers", "~> 4.1"