Check pull request for deviation before writing comments

[mmozuras]

GithubPullRequestFormatter bug:

If new commits are added to a pull request, Pronto sometimes writes comments on incorrect lines. Before doing that, it should check whether pull request hasn't changed.

Reported by @ljank

[Linuus]

@mmozuras Was this fixed? I seem to get this issue sometimes. I run the master version from github.

[mmozuras]

@Linuus I considered it fixed, but it was reproduced in another way today. Reopening again and will try to figure it out.

[somebody32]

Got the same issue today. But pronto messes positions even without pr changes at all, just comments on the wrong lines.

Fixed by changing line.position to message.line.position https://github.com/mmozuras/pronto/blob/master/lib/pronto/formatter/github_pull_request_formatter.rb#L21

but don't think that this is a proper fix

[mmozuras]

PRs from @jhass fix this. Currently unreleased in master.