add phpunit to composer.json

composer.json

@@ -22,7 +22,13 @@
    "require": {
       "php": ">=5.3.0"
    },
+   "require-dev": {
+       "phpunit/phpunit": "4.5.*"
+   },
    "autoload": {
       "classmap": ["AltoRouter.php"]
+   },
+   "scripts": {
+     "test": "vendor/bin/phpunit AltoRouterTest.php"
    }
 }