coinbase.go
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
}
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
}
// GetCurrencies gets all currency names and ISO's