Prepare for stable release

Author: nicolas-grekas

composer.json

@@ -3,7 +3,6 @@
     "type": "project",
     "license": "MIT",
     "description": "A skeleton to start a new Symfony website",
-    "minimum-stability": "dev",
     "require": {
         "php": "^7.2.5",
         "ext-ctype": "*",
@@ -83,9 +82,6 @@
         "symfony/symfony": "*"
     },
     "extra": {
-        "branch-alias": {
-            "dev-master": "5.1-dev"
-        },
         "symfony": {
             "allow-contrib": false,
             "require": "5.1.*"