more refactoring for dependency injection.

laravel/response.php

@@ -1,5 +1,16 @@
 <?php namespace Laravel;
 
+interface Renderable {
+
+	/**
+	 * Get the evaluated string contents of the object.
+	 *
+	 * @return string
+	 */
+	public function render();
+
+}
+
 class Response implements Renderable {
 
 	/**