Remove non-existing 1.15.1 version from changelog

Author: Christopher J. Brody

README.md

@@ -247,7 +247,6 @@ changelog
 ---------
 
 *  _1.16.0_ Fix `dependencies` to prevent major package updates
-*  _1.15.1_ Use coffeescript@1 to avoid potentially breaking change in a minor release
 *  _1.15.0_ Switch to coffeescript package
 *  _1.14.6_ Update dependencies to resolve `npm audit` issues
 *  _1.14.5_ Using ~ instead of ^ for reporter version (thanks to [Maxim-Filimonov](https://github.com/Maxim-Filimonov))