Update CHANGELOG.

Author: theengineear

CHANGELOG.md

@@ -8,6 +8,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Updated
 - `plotly.plotly.create_animations` and `plotly.plotly.icreate_animations` now return appropriate error messages if the response is not successful.
+- `frames` are now integrated into GRAPH_REFERENCE and figure validation.
 
 ### Changed
 - The plot-schema from `https://api.plot.ly/plot-schema` is no longer updated on import.