Add a CLA

[terinjokes]

See #20 (comment).

We should probably get a sign-off from everyone who's already contributed, and get sign-offs going forward.

[aaronpk]

It'd be worth adding a CONTRIBUTING.md file that says contributors agree to release their work under CC0. I don't think it's a problem to add that now, even before all existing contributors have officially signed off on CC0. At least that way all new contributions will be clean.

[RichardLitt]

Pinging @mairin @yoshuawuyts - you two are the only other contributors to this. Are you OK with this work being CC0, going forward?

[yoshuawuyts]

Sure, I'm happy to waiver any rights to contributions I made

…

On Wed, Jun 14, 2017, 14:34 Richard Littauer ***@***.***> wrote: Pinging @mairin <https://github.com/mairin> @yoshuawuyts <https://github.com/yoshuawuyts> - you two are the only other contributors to this. Are you OK with this work being CC0, going forward? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#22 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ACWlekQphVebY21I6p3DcbFT04fBa7Jxks5sD9MxgaJpZM4K1_4o> .

[terinjokes]

@aaronpk I'll definitely added a contributing along with the CLA shortly.

[mairin]

I'm totally cool with CC0.