code: func (c *Client) ListEmojis(ctx context.Context) (map[string]string, *Response, error) {
  	req, err := c.NewRequest("GET", "emojis", nil)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	var emoji map[string]string
  	resp, err := c.Do(ctx, req, &emoji)
  	if err != nil {
  		return nil, resp, err
  	}
  
  	return emoji, resp, nil
  }
docs: // ListEmojis returns the emojis available to use on GitHub.
  //
  // GitHub API docs: https://developer.github.com/v3/emojis/