Added Laravel 6 support

Author: bagsiz

composer.json

@@ -1,6 +1,6 @@
 {
   "name": "unisharp/laravel-filemanager",
-  "description": "A file upload/editor intended for use with Laravel 5 and CKEditor / TinyMCE",
+  "description": "A file upload/editor intended for use with Laravel 6 and CKEditor / TinyMCE",
   "license": "MIT",
   "keywords": [
     "filemanager",
@@ -27,11 +27,11 @@
     "ext-exif": "*",
     "ext-fileinfo": "*",
     "intervention/image": "2.*",
-    "illuminate/config": "5.4.* || 5.5.* || 5.6.* || 5.7.* || 5.8.*",
-    "illuminate/filesystem": "5.4.* || 5.5.* || 5.6.* || 5.7.* || 5.8.*",
-    "illuminate/support": "5.4.* || 5.5.* || 5.6.* || 5.7.* || 5.8.*",
-    "illuminate/http": "5.4.* || 5.5.* || 5.6.* || 5.7.* || 5.8.*",
-    "illuminate/container": "5.4.* || 5.5.* || 5.6.* || 5.7.* || 5.8.*"
+    "illuminate/config": "5.4.* || 5.5.* || 5.6.* || 5.7.* || 5.8.* || 6.*.*",
+    "illuminate/filesystem": "5.4.* || 5.5.* || 5.6.* || 5.7.* || 5.8.* || 6.*.*",
+    "illuminate/support": "5.4.* || 5.5.* || 5.6.* || 5.7.* || 5.8.* || 6.*.*",
+    "illuminate/http": "5.4.* || 5.5.* || 5.6.* || 5.7.* || 5.8.* || 6.*.*",
+    "illuminate/container": "5.4.* || 5.5.* || 5.6.* || 5.7.* || 5.8.* || 6.*.*"
   },
   "require-dev": {
     "phpunit/phpunit": "^6.2",