Minor adjustment to Guzzle requirements

Author: robbanl

composer.json

@@ -13,7 +13,7 @@
     ],
     "require": {
         "php": ">=7.0",
-        "guzzlehttp/guzzle": "^6.3 || ^7.0",
+        "guzzlehttp/guzzle": "^6.3 || ^6.5 || ^7.0",
         "illuminate/events": "~5.5 || ~6.0 || ~7.0 || ~8.0 || ~9.0",
         "illuminate/notifications": "~5.5 || ~6.0 || ~7.0 || ~8.0 || ~9.0",
         "illuminate/support": "~5.5 || ~6.0 || ~7.0 || ~8.0 || ~9.0"