feature #1122 Updated to Symfony 5.1.0 stable version (javiereguiluz)

This PR was merged into the master branch.

Discussion
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Updated to Symfony 5.1.0 stable version

Commits
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c2eefa7 Updated to Symfony 5.1.0 stable version

Author: javiereguiluz

composer.json

@@ -3,7 +3,7 @@
     "license": "MIT",
     "type": "project",
     "description": "Symfony Demo Application",
-    "minimum-stability": "dev",
+    "minimum-stability": "stable",
     "prefer-stable": true,
     "replace": {
         "symfony/polyfill-php70": "*",