IHF: phpunit added.

Author: dmitry-ivanov

composer.json

@@ -16,6 +16,9 @@
         "symfony/process": "^3.0",
         "symfony/var-dumper": "^3.0"
     },
+    "require-dev": {
+        "phpunit/phpunit": "^5.5"
+    },
     "autoload": {
         "files": ["src/autoload.php"]
     }