[1.x] Allow v6 of symphony/http-client (#14)

Author: charlielangridge

composer.json

@@ -18,7 +18,7 @@
         "php": "^7.3|^8.0",
         "illuminate/support": "^6.0|^7.0|^8.0|^9.0",
         "joelbutcher/facebook-graph-sdk": "^6.0.0",
-        "symfony/http-client": "^5.3"
+        "symfony/http-client": "^5.3|^6.0"
     },
     "require-dev": {
         "mockery/mockery": "^1.4.2",