Normalize redirects

in the http.rb:

redirect_to = response.is_a?(Net::HTTPRedirection) ?  URI(response['location']): nil

should be

redirect_to = response.is_a?(Net::HTTPRedirection) ?  URI(response['location']).normalize : nil

(added .normalize)
Otherwise we run crash because we run into redirects like "http://www.example.org"
The current crawler doesn't allow root level redirects, sanitizing input would still would be the correct thing to do though:)