Updated to tagged contracts

Author: WyriHaximus

composer.json

@@ -14,7 +14,7 @@
         "ext-parallel": "*",
         "moneyphp/money": "^3.2.1",
         "ocramius/package-versions": "^1.4",
-        "react-parallel/contracts": "dev-master",
+        "react-parallel/contracts": "^1.0",
         "react/event-loop": "^1.1",
         "react/promise": "^2.7",
         "thecodingmachine/safe": "v1.0.0 as v0.1.17",