Release note: https://github.com/rdoc/rdoc/blob/b825775647f62c5b525e9780a28ff2fbb1d5bf6f/History.rdoc#500--2016-11-05

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56586 b2dd03c8-39d4-4d8f-98ff-823fe69b080e