upgrade laravel to 5.7

Author: adenvt

composer.json

@@ -8,7 +8,7 @@
     "php": "^7.1.3",
     "fideloper/proxy": "^4.0",
     "guzzlehttp/guzzle": "^6.3",
-    "laravel/framework": "5.6.*",
+    "laravel/framework": "5.7.*",
     "laravel/tinker": "^1.0"
   },
   "require-dev": {