Added support for perform_substitutions transmissions option

Author: darrensmith223

CHANGELOG.md

@@ -6,7 +6,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - [Compare to latest release][unreleased]
 
 ## [1.3.10] - 2021-04-29
-- [#215](https://github.com/SparkPost/python-sparkpost/pull/219) Support for perform_substitution
+- [#219](https://github.com/SparkPost/python-sparkpost/pull/219) Support for perform_substitution
 
 ## [1.3.9] - 2021-04-29
 - [#215](https://github.com/SparkPost/python-sparkpost/pull/215) Fix bug in _translate_keys that affects non-nested parameters