Add Laravel 5.8 support

Author: driesvints

composer.json

@@ -13,9 +13,9 @@
         "php": ">=7.1.3",
         "ext-dom": "*",
         "ext-json": "*",
-        "illuminate/database": "~5.7.0",
-        "illuminate/http": "~5.7.0",
-        "illuminate/support": "~5.7.0",
+        "illuminate/database": "~5.7.0|~5.8.0",
+        "illuminate/http": "~5.7.0|~5.8.0",
+        "illuminate/support": "~5.7.0|~5.8.0",
         "mockery/mockery": "^1.0",
         "phpunit/phpunit": "^7.0|^8.0",
         "symfony/console": "^4.2",
@@ -25,7 +25,7 @@
         "symfony/http-kernel": "^4.2"
     },
     "require-dev": {
-        "laravel/framework": "~5.7.0"
+        "laravel/framework": "~5.7.0|~5.8.0"
     },
     "autoload": {
         "psr-4": {