Update composer.json (#8)

Allow guzzle 7

Author: neoteknic

composer.json

@@ -18,7 +18,7 @@
     "require": {
         "php" : "^7.0|^8.0",
         "illuminate/support": "~5.5.0|~5.6.0|~5.7.0|~5.8.0|^6.0|^7.0|^8.0",
-        "graham-campbell/guzzle-factory": "^3.0"
+        "graham-campbell/guzzle-factory": "^3.0|^4.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^6.2|^7.0|^8.0|^9.0",