Please add a license to this repo

[Misha Brukman]

First, thank you for sharing this project with us!

Could you please add an explicit LICENSE file to the repo so that it's clear
under what terms the content is provided, and under what terms user
contributions are licensed?

Per GitHub docs on licensing:

[...] without a license, the default copyright laws apply, meaning that you
retain all rights to your source code and no one may reproduce, distribute,
or create derivative works from your work. If you're creating an open source
project, we strongly encourage you to include an open source license.

Thanks!

[Denny Britz]

Sure! Done in 7ae6be2