update composer.json

composer.json

 {
-    "name": "Silex",
-    "type": "Library",
+    "name": "silex",
+    "type": "library",
     "description": "The PHP micro-framework based on the Symfony2 Components",
     "keywords": ["microframework"],
     "homepage": "http://silex.sensiolabs.org",
@@ -18,13 +18,12 @@
     ],
     "require": {
         "php": ">=5.3.2",
-        "Pimple": ">=1.0.0",
-        "Symfony-BrowserKit": ">=2.0.0",
-        "Symfony-CssSelector": ">=2.0.0",
-        "Symfony-DomCrawler": ">=2.0.0",
-        "Symfony-EventDispatcher": ">=2.0.0",
-        "Symfony-HttpFoundation": ">=2.0.0",
-        "Symfony-HttpKernel": ">=2.0.0",
-        "Symfony-Routing": ">=2.0.0"
+        "pimple": ">=1.0.0",
+        "symfony/browser-kit": "2.0.*",
+        "symfony/dom-crawler": "2.0.*",
+        "symfony/event-dispatcher": "2.0.*",
+        "symfony/http-foundation": "2.0.*",
+        "symfony/http-kernel": "2.0.*",
+        "symfony/routing": "2.0.*"
     }
 }