Merge pull request #11 from jstolp/add-content-length-0-on-start-tran…

…saction

Adding Content-Length: 0 Head on PUT start transaction call

src/SignhostClient.php

@@ -90,7 +90,12 @@ public function performRequest(string $endpoint, string $method, $data = null, $
             if ("GET" === $method || "HEAD" === $method && !isset($filePath)) {
                 unset($headers[0]); // unset Content-Type
             }
-
+
+            // for start transaction, SignHost will require the content-lenth: 0 header.
+            if (false !== strpos($endpoint, 'start')) {
+                $headers[] = "Content-Length: 0";
+            }
+
             // Initialize a cURL session
             return $this->performCURLRequest(
                 $method,