Update versions in composer.json

Author: nicolas-grekas

composer.json

@@ -38,12 +38,10 @@
     ],
     "minimum-stability": "dev",
     "extra": {
-        "branch-alias": {
-            "dev-master": "3.4-dev"
-        },
         "thanks": {
             "name": "phpunit/phpunit",
             "url": "https://github.com/sebastianbergmann/phpunit"
         }
-    }
+    },
+    "version": "3.4.x-dev"
 }