Reference individual contracts packages

Author: nicolas-grekas

composer.json

@@ -21,7 +21,7 @@
     "require": {
         "php": "^7.1.3",
         "psr/log": "^1.0",
-        "symfony/contracts": "^1.1",
+        "symfony/http-client-contracts": "^1.1",
         "symfony/polyfill-php73": "^1.11"
     },
     "require-dev": {