Would be good to have changelog for releases

[repi]

As well as pushing git tags for the published releases. Would highly recommend having that together with a CHANGELOG.md and add the changelog items to the GitHub release after one has released it and pushed the tag. So everyone can see what are the user facing changes between versions without having to manually diff the code.

One can diff the code with for example http://diff.rs/redis-async/0.14.2/0.16.0 but not the best practice as more cumbersome than providing a changelog / release notes