Merge pull request #1 from Fichtme/patch-1

Update composer.json

Author: imbue

composer.json

@@ -17,7 +17,7 @@
   ],
   "require": {
     "php": "^7.2",
-    "guzzlehttp/guzzle": "^6.3"
+    "guzzlehttp/guzzle": "~4.0|~5.0|~6.0|~7.0"
   },
   "require-dev": {
     "phpunit/phpunit": "^5.7 || ^6.5 || ^7.1"