code: func (c *Client) Zen(ctx context.Context) (string, *Response, error) {
  	req, err := c.NewRequest("GET", "zen", nil)
  	if err != nil {
  		return "", nil, err
  	}
  
  	buf := new(bytes.Buffer)
  	resp, err := c.Do(ctx, req, buf)
  	if err != nil {
  		return "", resp, err
  	}
  
  	return buf.String(), resp, nil
  }
docs: // Zen returns a random line from The Zen of GitHub.
  //
  // see also: http://warpspire.com/posts/taste/