Remove branch-alias definition as per reactphp/reactphp#343

WyriHaximus · web-flow · commit 30c6ef5f3562 · 2016-07-06T17:43:15.000+02:00
diff --git a/composer.json b/composer.json
@@ -15,10 +15,5 @@
         "psr-4": {
             "React\\EventLoop\\": "src"
         }
-    },
-    "extra": {
-        "branch-alias": {
-            "dev-master": "0.5-dev"
-        }
     }
 }
