remove references to "Silex"

Author: a1812

README.md

@@ -3,8 +3,7 @@ HttpKernel Component
 
 The HttpKernel component provides a structured process for converting a Request
 into a Response by making use of the EventDispatcher component. It's flexible
-enough to create a full-stack framework (Symfony), a micro-framework (Silex) or
-an advanced CMS system (Drupal).
+enough to create full-stack frameworks, micro-frameworks or advanced CMS systems like Drupal.
 
 Resources
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