Show a git-diff of NEWS.md on update

[cstjean]

Right now, there aren't a lot of ways for package maintainers to communicate breaking changes and updates with their users. Could Pkg.update(news=true) display the git-diff of NEWS.md for each updated package?

[StefanKarpinski]

I like that idea 👍.

[nalimilan]

As noted on Discourse, it would make sense to use the GitHub release notes for this. A git log is generally hard to read even for developers, and NEWS.md files are more tedious to update (since you need to commit the changes before tagging the release).

[juliohm]

I vote for having this feature tightly integrated with attobot as proposed on Discourse. Ideally, changelogs would be extracted from GitHub releases directly without any impact on our current workflow.

[KristofferC]

More discussion at JuliaLang/Pkg.jl#176. Discussion can continue there.