Release Summary for 4.2.0
  Difference between master and 4.1
  * kazoo-core/README.md
  * [PISTON-470: media files for ACDc announcements (#6)](https://github.com/2600hz/kazoo-sounds/commit/3fcf1f848b507684e7b085eee7e6c75836469919) by Daniel Finke
  * [README: Fixed sup command (#5)](https://github.com/2600hz/kazoo-sounds/commit/e0307c5251e719bec97d2a3ce1eccb63527eed89) by sergey-safarov
 -- 2600Hz Offical <packages@2600hz.com>  Thu, 28 Sep 2017 19:17:49 +0000
