[SwiftmailerBundle] added swiftmailer dependency in composer.json

src/Symfony/Bundle/SwiftmailerBundle/composer.json

@@ -17,6 +17,7 @@
         }
     ],
     "require": {
-        "php": ">=5.3.2"
+        "php": ">=5.3.2",
+        "swiftmailer/swiftmailer": ">=4.1.2"
     }
 }