Update CHANGELOG

Author: duckontheweb

CHANGELOG.md

@@ -11,6 +11,7 @@
 - Migration for `sar:type` -> `sar:product_type` and `sar:polarization` ->
   `sar:polarizations` for pre-0.9 catalogs
   ([#556](https://github.com/stac-utils/pystac/pull/556))
+- Migration from `eo:epsg` -> `proj:epsg` for pre-0.9 catalogs ([#557](https://github.com/stac-utils/pystac/pull/557))
 
 ### Removed