Handle github release

[MoOx]

I think that script I am using might give you an idea

https://github.com/MoOx/setup/blob/master/bin/npmrelease

It grab the section in changelog that fit the version in package.json to create a annotated github release.

This gives this kind of results (example on the 2 latests releases) https://github.com/cssnext/cssnext/releases)

[defunctzombie]

This would be pretty cool. I would review or PR or look into it next time I get around to working on this.