Bug with Attachments

[HunterNyan]

QuickBooks-V3-PHP-SDK/src/_Samples/UploadAttachment.php

Line 131 in a4139a9

$resultObj = $dataService->Upload(base64_decode($imageBase64[$sendMimeType]),

From my understanding, this "base64_decode" should not exist as the function expects the base64 of the attachment to sent.

[bomshteyn]

PR: #432