code: func (c Client) GetCurrencies() ([]currency, error) {
  	holder := [][]string{}
  	if err := c.Get("currencies", nil, &holder); err != nil {
  		return nil, err
  	}
  	finalData := []currency{}
  	for _, curr := range holder {
  		class := currency{
  			Name: curr[0],
  			Iso:  curr[1],
  		}
  		finalData = append(finalData, class)
  	}
  	return finalData, nil
  }
docs: // GetCurrencies gets all currency names and ISO's