Add changelog

[thisjustin]

It would be very helpful if a changelog was added to the repo to help us identify new features, fixes and also breaking changes with each release.

See http://keepachangelog.com/

[zhenlineo]

Do you mean this one? https://github.com/neo4j/neo4j-python-driver/wiki/1.0-changelog

Or do you want the changelog comes with the repo's source code directly?

[thisjustin]

@zhenlineo ah, I had no idea it was there. I always check for changelog.md in the root of repos. Just a link from the readme would suffice if you've already been keeping one in the wiki.