Pi 3 Home Assistant top, zip/cable tie bottom

Raspberry Pi 3 case based on design by [0110-M-P](https://www.thingiverse.com/thing:922740).

My friend wanted a Pi case which could be mounted with cable ties to run a [Home Assistant](https://home-assistant.io/) server.

**Top**
* Home Assistant "tree" logo - [source](https://github.com/home-assistant/home-assistant-assets)
* Interior support for logo
* No GPIO or ribbon cable holes

**Bottom**
* Cable/zip tie mounting holes along one side.
* M3 machine screws secure Pi and top