Update composer.json from skeleton repo

Author: petericebear

composer.json

@@ -13,9 +13,8 @@
     ],
     "require": {
         "php": ">=5.6.4",
-        "illuminate/notifications": "^5.3@dev",
-        "illuminate/support": "^5.3@dev",
-        "illuminate/events": "^5.3@dev",
+        "illuminate/notifications": "^5.3",
+        "illuminate/support": "^5.1|^5.2|^5.3",
         "messagebird/php-rest-api": "^1.4"
     },
     "require-dev": {