Add Laravel 7 support

Author: Lloople

composer.json

@@ -14,11 +14,11 @@
     "type": "library",
     "require": {
         "php": "^7.1",
-        "laravel/framework": "^5.7|^6.0"
+        "laravel/framework": "^5.7|^6.0|^7.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7.2",
-        "orchestra/testbench": "^3.7|^4.0"
+        "phpunit/phpunit": "^7.2|^8.0",
+        "orchestra/testbench": "^3.7|^4.0|^5.0"
     },
     "autoload": {
         "psr-4": {