added key and session tasks.

laravel/cli/dependencies.php

@@ -35,6 +35,17 @@ IoC::singleton('task: key', function()
 	return new Tasks\Key;
 });
 
+/**
+ * The session task is responsible for performing tasks related
+ * to the session store of the application. It can do things
+ * such as generating the session table or clearing expired
+ * sessions from storage.
+ */
+IoC::singleton('task: session', function()
+{
+	return new Tasks\Session;
+});
+
 /**
  * The bundle repository is responsible for communicating with
  * the Laravel bundle sources to get information regarding any