Replace defunct URL.

Author: seth-mg

examples/categories.rb

@@ -10,7 +10,7 @@
                 RosetteAPI.new(api_key)
               end
 
-categories_url_data = 'https://onlocationvacations.com/2018/02/06/downton-abbey-exhibition-extended-april-2-nyc/'
+categories_url_data = 'https://www.rosette.com/about/'
 begin
   params = DocumentParameters.new(content_uri: categories_url_data)
   response = rosette_api.get_categories(params)