Allow guzzlehttp/guzzle v7.0

Author: mvdnbrk

composer.json

@@ -20,7 +20,7 @@
         "php": "^7.2",
         "ext-json": "*",
         "composer/ca-bundle": "^1.2",
-        "guzzlehttp/guzzle": "^6.4",
+        "guzzlehttp/guzzle": "^6.4 || ^7.0",
         "lcobucci/jwt": "^3.3",
         "ramsey/uuid": "^3.8 || ^4.0",
         "tightenco/collect": "^5.8 || ^6.0 || ^7.0"