Update CHANGES (releng for 2.1).

Change-Id: I4f318d6c4487836b71476754014094873f20413f
Signed-off-by: Piotr Sikora <piotr.sikora@frickle.com>

Author: PiotrSikora

CHANGES

@@ -1,3 +1,8 @@
+2013-03-19    VERSION 2.1
+    * When enabled, cache purge will now catch all requests with
+      PURGE (or specified) method, even if cache isn't configured.
+      Previously, it would pass such requests to the upstream.
+
 2012-12-07    VERSION 2.0
     * Add alternative "same location" syntax.
       From CloudFlare.