fix json sintaxe

Author: Sena

composer.json

@@ -12,7 +12,7 @@
         "phpunit/phpunit": "4.8.*"
     },
     "require-dev": {
-        "phpunit/phpunit": "4.8.*",
+        "phpunit/phpunit": "4.8.*"
     },
     "minimum-stability": "dev",
     "prefer-stable": true