Fix php version for v2.0

Author: yoanm

README.md

@@ -17,7 +17,7 @@ See [yoanm/jsonrpc-params-symfony-constraint-doc-sdk](https://github.com/yoanm/p
 ## Versions
 
 - Symfony v3/4 - PHP >=7.1 : `^v1.0` 
-- Symfony v4/5 - PHP >=7.1 : `^v2.0`
+- Symfony v4/5 - PHP >=7.2 : `^v2.0`
 
 ⚠️⚠️ `v0.2.0` is replaced by `v1.0.0` ! ⚠️⚠️