Remove obsolete branch alias

composer.json

@@ -25,7 +25,7 @@
     "require-dev": {
         "phpunit/phpunit": "^5.7",
         "squizlabs/php_codesniffer": "^3.0",
-        "silverstripe/versioned": "^1@dev"
+        "silverstripe/versioned": "^1"
     },
     "extra": {
         "screenshots": [
@@ -35,10 +35,7 @@
         "expose": [
             "css",
             "javascript"
-        ],
-        "branch-alias": {
-            "dev-master": "4.x-dev"
-        }
+        ]
     },
     "replace": {
         "ajshort/silverstripe-gridfieldextensions": "self.version",