Fix error: private method `open' called for URI:Module by hanachin · Pull Request #27 · amatsuda/gem-src

In ruby version < 2.5, URI.open is private method root@107ef8fe8980:/all-ruby# ALL_RUBY_SINCE=ruby-2.0.0 ./all-ruby -ropen-uri -e 'p URI.respond_to?(:open)' ruby-2.0.0-p0 false ......