Negative PayableRoundingAmount

[hallsten]

Thanks for a helpful library! Discovered a problem with RoundingAmount.

cbc:PayableRoundingAmount can be negative and positive, but the element only shows if the amount is positive. Suggest changing line 831 in UblWriter.php from:
if ($totals->roundingAmount > 0) {

to:
if ($totals->roundingAmount <> 0) {

Many thanks

[josemmo]

@hallsten, thanks for the reporting this! Will fix it in the next release.