Merge pull request #8 from pdffiller/qless-php-3.8.1

Up to latest qless-php

Author: osadchyi-s

composer.json

@@ -16,7 +16,7 @@
     ],
     "require": {
         "ext-json": "*",
-        "pdffiller/qless-php": "3.6.1"
+        "pdffiller/qless-php": "3.8.1"
     },
     "require-dev": {
         "illuminate/events": "5.6.*|5.7.*",