Could you add a LICENSE file?

[Hiroaki Nakamura]

First of all, thanks for creating and sharing a nice software!

Could you add a LICENSE file?
Choosing an OSS license doesn’t need to be scary - ChooseALicense.com maybe helpful when you choose a license.
I hope you choose a permissive licenses like MIT and Apache.
Thanks!

[Nils Lagerkvist]

8b924a0 Added licensen file

[Hiroaki Nakamura]

Thanks!