Add CL entry

CHANGELOG.md

@@ -8,6 +8,9 @@
 * Our super spiffy logo, designed by [mercedes](https://github.com/mercedes-stripe), is now included at the top of the README!
 * Refactor internals to use a new intermediary metric struct to facilitate new plugins. Thanks [gphat](https://github.com/gphat)!
 
+## Improvements
+* Introduced a new `metricSink` which provides a common interface for metric backends. In an upcoming release all plugins will be converted to this interface. Thanks [gphat](https://github.com/gphat)!
+
 ## Deprecations
 * `veneur-emit` no longer supports the `-config` argument, as it's no longer possible to reliably detect which statsd host/port to connect to. The `-hostport` option now takes a URL of the same form `statsd_listen_addresses` takes to explicitly tell it what address it should send to.