Updated change-log.

Signed-off-by: Taylor Otwell <taylorotwell@gmail.com>

changes.txt

@@ -17,4 +17,5 @@ Changes for 3.1:
 	- Postgres "unique" indexes are now added with ADD CONSTRAINT
 	- Added "Event::until" method.
 	- Added "memory" cache and session drivers.
-	- Added controller::detect method.
+	- Added controller::detect method.
+	- Added Cache::forever method.