Updad composer to support 5.4

Author: pionl

composer.json

@@ -2,7 +2,7 @@
   "name": "pion/laravel-eloquent-position",
   "description": "Position logic for Eloquent models with minimum setup",
   "require": {
-    "laravel/framework": "5.1.* || 5.2.* || 5.3.*"
+    "laravel/framework": "5.1.* || 5.2.* || 5.3.* || 5.4.*"
   },
   "require-dev": {
     "squizlabs/php_codesniffer": "2.*"