Update composer.json

Author: driesvints

composer.json

@@ -11,7 +11,7 @@
     ],
     "require": {
         "php": "^7.2",
-        "guzzlehttp/guzzle": "^6.0",
+        "guzzlehttp/guzzle": "^6.0|^7.0",
         "illuminate/support": "^6.0|^7.0",
         "symfony/console": "^4.3|^5.0",
         "symfony/process": "^4.3|^5.0"