changelog update for spyOnProperty, jestjs#5753

Author: thomasjinlo

CHANGELOG.md

@@ -23,6 +23,8 @@
 * `[jest-cli]` Add `isSerial` property that runners can expose to specify that
   they can not run in parallel
   [#5706](https://github.com/facebook/jest/pull/5706)
+* `[jest-mock]` Update `spyOnProperty` to support spying on the prototype
+  chain ([#5753](https://github.com/facebook/jest/pull/5753))
 
 ### Fixes