Merge branch '2.4'

* 2.4:
  updated min stability to beta
  updated VENDORS for 2.4.0-BETA1

Author: fabpot

composer.json

@@ -39,7 +39,7 @@
     "config": {
         "bin-dir": "bin"
     },
-    "minimum-stability": "dev",
+    "minimum-stability": "beta",
     "extra": {
         "symfony-app-dir": "app",
         "symfony-web-dir": "web",