code: func (b *Bittrex) GetCurrencies() (currencies []Currency, err error) {
  	r, err := b.client.do("GET", "public/getcurrencies", "", false)
  	if err != nil {
  		return
  	}
  	var response jsonResponse
  	if err = json.Unmarshal(r, &response); err != nil {
  		return
  	}
  	if err = handleErr(response); err != nil {
  		return
  	}
  	err = json.Unmarshal(response.Result, &currencies)
  	return
  }
docs: // GetCurrencies is used to get all supported currencies at Bittrex along with other meta data.