Update release notes

Signed-off-by: Sahas Subramanian <[email protected]>

Author: shsms

RELEASE_NOTES.md

@@ -12,6 +12,8 @@
 
 - `LatestValueCache` now takes an optional `key` function, which returns the key for each incoming message, and the latest value for each key is cached and can be retrieved separately.  
 
+- `LatestValueCache` got a new `clear` method that clears the latest value.  When an optional `key` argument is specified, it clears the value only for that key.
+
 ## Bug Fixes
 
 <!-- Here goes notable bug fixes that are worth a special mention or explanation -->