lock laravel 5 to a specific commit

composer.json

@@ -17,7 +17,7 @@
   ],
   "type": "project",
   "require": {
-    "laravel/framework": "~5.0",
+    "laravel/framework": "dev-master#ba916851321b9233cb56a0fb1deb41043b7df5fb",
     "laravel/elixir": "~1.0",
     "illuminate/html": "~5.0",
     "pingpong/modules": "1.*",