code: func (s *AuthorizationsService) Revoke(ctx context.Context, clientID string, token string) (*Response, error) {
  	u := fmt.Sprintf("applications/%v/tokens/%v", clientID, token)
  
  	req, err := s.client.NewRequest("DELETE", u, nil)
  	if err != nil {
  		return nil, err
  	}
  
  	return s.client.Do(ctx, req, nil)
  }
docs: // Revoke an authorization for an application.
  //
  // Note that this operation requires the use of BasicAuth, but where the
  // username is the OAuth application clientID, and the password is its
  // clientSecret. Invalid tokens will return a 404 Not Found.
  //
  // GitHub API docs: https://developer.github.com/v3/oauth_authorizations/#revoke-an-authorization-for-an-application