code: def __check_looks_like_uri(self, uri):
          
          if uri.split('/')[2] == 'raw.githubusercontent.com':
              return True
          elif uri.split('/')[2] == 'github.com':
              if uri.split('/')[5] == 'raw':
                  return True
          else:
              raise GithubFileNotFound('URI %s is not a valid link to a raw file in Github' % uri)
docs: Checks the URI looks like a RAW uri in github:
  
          - 'https://raw.githubusercontent.com/github/hubot/master/README.md'
          - 'https://github.com/github/hubot/raw/master/README.md'
  
          :param uri: uri of the file