Add entry to CHANGELOG

Author: mulimoen

CHANGELOG.md

@@ -61,6 +61,10 @@
   allowing fixed-size arrays of arbitrary sizes.
 - The `ndarray` dependency has been updated to `0.15`.
 
+### Fixed
+
+- A memory leak of handles has been identified and fixed.
+
 ## 0.7.1
 
 ### Added