Merge pull request #12 from reactphp-parallel/add-metrics

Add metrics

Author: WyriHaximus

composer.json

@@ -23,6 +23,7 @@
         "thecodingmachine/safe": "^1.2",
         "wyrihaximus/constants": "^1.5",
         "wyrihaximus/iterator-or-array-to-array": "^1.1",
+        "wyrihaximus/metrics": "dev-master",
         "wyrihaximus/string-get-in": "^1.0"
     },
     "require-dev": {