update CHANGELOG with leader election changes

Signed-off-by: Andrew Sy Kim <kiman@vmware.com>

CHANGELOG-1.1.md

@@ -3,6 +3,10 @@
 ## Deprecations
 
 * Command line flag `-connection-timeout` is deprecated and has no effect.
+* Command line flag `--leader-election-identity` is deprecated and has no effect.
+* Command line flag `--leader-election-type` is deprecated. Support for Configmaps-based
+  leader election will be removed in the future in favor of Lease-based leader election.
+  The default currently remains as `configmaps` for backwards compatibility.
 
 ## Notable Features
 
@@ -14,6 +18,8 @@
 
 * README.md has been significantly enhanced. ([#130](https://github.com/kubernetes-csi/external-attacher/pull/130))
 
+* Add support for Lease based leader election. Enable this by setting `--leader-election-type=leases` ([#135](https://github.com/kubernetes-csi/external-attacher/pull/135))
+
 ## Other notable changes
 
 * Update vendor to bring in updated CSI translation library ([#133](https://github.com/kubernetes-csi/external-attacher/pull/133))