What is the best code review tool for GitHub projects?
The ideal tool would:
* have code reviews should happen on the pull-request level, not on an individual git commit level.
* provide diffs between subsequent commits added to the pull request.
* have a way to "resolve" comments added by reviewers, and show the reviewers a diff that illustrates that a fix was applied.
* auto-merge when a "LGTM" or approval is given by a project owner