add National Bank of Romania exchange rates data source

pkg/exchangerates/exchange_rates_datasource_container.go

@@ -41,6 +41,9 @@ func InitializeExchangeRatesDataSource(config *settings.Config) error {
 	} else if config.ExchangeRatesDataSource == settings.DanmarksNationalbankDataSource {
 		Container.Current = &DanmarksNationalbankDataSource{}
 		return nil
+	} else if config.ExchangeRatesDataSource == settings.NationalBankOfRomaniaDataSource {
+		Container.Current = &NationalBankOfRomaniaDataSource{}
+		return nil
 	} else if config.ExchangeRatesDataSource == settings.InternationalMonetaryFundDataSource {
 		Container.Current = &InternationalMonetaryFundDataSource{}
 		return nil