Fix on improve composer.json

* Fix duplicate require section
* PHPUnit on require-dev only

Author: soullivaneuh

composer.json

@@ -13,14 +13,14 @@
         }
     ],
     "require": {
-        "phpunit/phpunit": ">=3.7",
-        "sebastian/exporter": "1.*"
+        "php": ">=5.3",
+        "sebastian/exporter": "1.*",
+        "symfony/config": "2.*"
+    },
+    "require-dev": {
+        "phpunit/phpunit": ">=3.7"
     },
     "autoload": {
         "psr-4" : { "Matthias\\SymfonyConfigTest\\" : "" }
-    },
-    "require": {
-        "php": ">=5.3",
-        "symfony/config": "2.*"
     }
 }