Should normalize IDN properly

[dentarg]

twingly-url should normalize internationalized domain names (IDN) properly.

[13] pry(main)> Twingly::URL::Normalizer.normalize "http://www.åäö.se"
=> ["http://www.åäö.se/"]

[18] pry(main)> Addressable::URI.parse("http://www.åäö.se").normalize.to_s
=> "http://www.xn--4cab6c.se/"

Here is how the addressable gem does it:

• lib/addressable/uri.rb normalized_host
• lib/addressable/idna/pure.rb to_ascii