code: func (s *RepositoriesService) DeleteReleaseAsset(ctx context.Context, owner, repo string, id int64) (*Response, error) {
  	u := fmt.Sprintf("repos/%s/%s/releases/assets/%d", owner, repo, id)
  
  	req, err := s.client.NewRequest("DELETE", u, nil)
  	if err != nil {
  		return nil, err
  	}
  	return s.client.Do(ctx, req, nil)
  }
docs: // DeleteReleaseAsset delete a single release asset from a repository.
  //
  // GitHub API docs: https://developer.github.com/v3/repos/releases/#delete-a-release-asset