Special characters handling

* Fix README for python version
* Add discord-friendly unidecode function for channel names (avoiding
  special characted)
* Check if "items" is present before accessing in channel id request
  response

breadtube_bot/youtube_manager.py

@@ -76,6 +76,8 @@ class YoutubeManager:
                f'&forHandle=%40{channel_name}&key={self._api_key}')
         self._logger.debug('YoutubeManager: request channel id for channel %s', channel_name)
         _, info = self._request(url=url, request_timeout=request_timeout)
+        if 'items' not in info:
+            raise RuntimeError(f'No result found for channel named: {channel_name}')
         return info['items'][0]['id']
 
     @staticmethod