Reference individual contracts packages

Author: nicolas-grekas

composer.json

@@ -18,7 +18,7 @@
     "require": {
         "php": "^7.1.3",
         "symfony/cache": "~3.4|~4.0",
-        "symfony/contracts": "^1.0"
+        "symfony/service-contracts": "^1.1"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\ExpressionLanguage\\": "" },