Update composer.json for 2.4 release.

composer.json

@@ -13,11 +13,11 @@
     ],
     "require": {
         "php": ">=5.3.2",
-        "doctrine/common": "2.4.*@beta"
+        "doctrine/common": "~2.4"
     },
     "require-dev": {
         "phpunit/phpunit": "3.7.*",
-        "symfony/console": "2.*"
+        "symfony/console": "~2.0"
     },
     "suggest": {
         "symfony/console": "For helpful console commands such as SQL execution and import of files."
@@ -28,11 +28,6 @@
     "autoload": {
         "psr-0": { "Doctrine\\DBAL\\": "lib/" }
     },
-    "extra": {
-        "branch-alias": {
-            "dev-master": "2.5.x-dev"
-        }
-    },
     "archive": {
         "exclude": ["!vendor", "tests", "*phpunit.xml", ".travis.yml", "build.xml", "build.properties", "composer.phar"]
     }