feat: 支持 laravel 8.x

Author: jiannei

composer.json

@@ -12,11 +12,12 @@
         "php": "^7.2.5|^8.0"
     },
     "require-dev": {
-        "orchestra/testbench": "^5.0",
-        "phpunit/phpunit": "^8.5.8|^9.3.3",
-        "orchestra/database": "^5.0",
-        "jiannei/laravel-enum": "^2.0",
-        "league/fractal": "^0.19.2"
+        "orchestra/testbench": "^6.0",
+        "phpunit/phpunit": "^9.3.3",
+        "orchestra/database": "^6.0",
+        "jiannei/laravel-enum": "^3.0",
+        "league/fractal": "^0.19.2",
+        "laravel/legacy-factories": "^1.1"
     },
     "autoload": {
         "psr-4": {