Updated CHANGES for the new features merged in by PR
- Added ``transform_func`` & ``ylim_func`` keywords to ``interact()`` to
support user-defined light curve transformations and y-axis limits. [#600]
+- Added ``to_stringray()`` and ``from_stingray()`` to ``LightCurve`` to enable
+ interoperability with the `Stingray <https://stingraysoftware.github.io/>`_
+ spectral timing package. [#567]
+
1.4.1 (2019-11-18)
