add laravel 7 support

Author: samaasi

composer.json

@@ -16,7 +16,7 @@
    "minimum-stability": "stable",
    "require": {
     "php": "^5.4.0|^7.0",
-    "illuminate/support": "5.*|6.*",
+    "illuminate/support": "5.*|6.*|^7.0",
     "guzzlehttp/guzzle": "5.*|6.*"
    },
    "require-dev": {