SP-44 forcedBuyerSelectedTransactionCurrency should set the value on the invoice

Author: bobbrodie

src/main/java/com/bitpay/sdk/model/Invoice/Invoice.java

@@ -424,7 +424,7 @@ public void setBuyerSms(String _buyerSms) {
     // Response fields
     //
 
-    @JsonIgnore
+    @JsonProperty("forcedBuyerSelectedTransactionCurrency")
     public String getForcedBuyerSelectedTransactionCurrency() {
         return _forcedBuyerSelectedTransactionCurrency;
     }