Upgrading Corcel to match Laravel 7 requirements

Author: rezsk

composer.json

@@ -12,7 +12,7 @@
   ],
   "require": {
     "php": ">=7.2",
-    "jgrossi/corcel": "^3.0"
+    "jgrossi/corcel": "^4.0"
   },
   "require-dev": {
     "phpunit/phpunit": "^8.0"