chore: add support for Laravel 8

Author: pactode

composer.json

@@ -12,12 +12,12 @@
     ],
     "require": {
         "php": "^7.2.5",
-        "illuminate/database": "^6.0|^7.0",
-        "illuminate/support": "^6.0|^7.0"
+        "illuminate/database": "^6.0|^7.0|^8.0",
+        "illuminate/support": "^6.0|^7.0|^8.0"
     },
     "require-dev": {
         "mockery/mockery": "^1.2",
-        "orchestra/testbench": "^4.0|^5.0",
+        "orchestra/testbench": "^4.0|^5.0|^6.0",
         "phpunit/phpunit": "^7.0|^8.0|^9.0"
     },
     "autoload": {