CHANGELOG typo

Author: jonmmease

CHANGELOG.md

@@ -8,7 +8,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
  - Updated Plotly.js to version 1.49.4. See the
  [plotly.js CHANGELOG](https://github.com/plotly/plotly.js/blob/master/CHANGELOG.md#1494----2019-08-22)
  for more information
- - The width of a figure produced buy the `create_gantt` figure factory now resizes responsively ([#1724](https://github.com/plotly/plotly.py/pull/1724))
+ - The width of a figure produced by the `create_gantt` figure factory now resizes responsively ([#1724](https://github.com/plotly/plotly.py/pull/1724))
 
 ### Fixed
  - The name of the steps property of `graph_objects.indicator.Guage` has been renamed from `stepss` to `steps`