Updated composer.json to only support laravel 7

Author: le0daniel

composer.json

@@ -22,7 +22,7 @@
   },
   "require": {
     "php": "^7.2",
-    "laravel/framework": "^6||^7",
+    "laravel/framework": "^7",
     "intervention/image": "^2.5"
   }
 }