Updated CHANGELOG

Author: anselor

CHANGELOG.md

@@ -1,3 +1,10 @@
+## 1.3.1 (August 6, 2020)
+* Bug Fixes
+    * Fixed issue determining whether an argparse completer function required a reference to a containing
+       CommandSet. Also resolves issues determining the correct CommandSet instance when calling the argparse 
+       argument completer function.  Manifested as a TypeError when using `cmd2.Cmd.path_complete` as a completer 
+       for an argparse-based command defined in a CommandSet
+
 ## 1.3.0 (August 4, 2020)
 * Enhancements
     * Added CommandSet - Enables defining a separate loadable module of commands to register/unregister