add something else to CHANGELOG for unreleased 4.1.0

Author: Roguelazer

CHANGELOG.md

@@ -3,6 +3,7 @@
 * add `original_exception` to `easypost.Error` in cases where we are re-raising an underlying error (e.g., an HTTP exception)
 * fix a bunch of flake8 warnings
 * [potentially-breaking] soft-deprecate Python 3.3 and 3.4. these have been dropped by most of the libraries we use, so probably don't work anyway.
+* Swap GET to POST on Refund method
 
 ### 4.0.2 2020-05-05
 * cleaned up how the `__version__` attribute is populated to no longer throw warnings (#95, #98, #104)