Distinguish committer and author

Sometimes you have commits that come in where the committer is different than the author. This happens frequently on Open Source projects or if you happen to have a bot that's automatically committing. It would be helpful to distinguish commits coming in just from the author and ones from a committer/bot.

- repo is not a variable in the rescue scope

**Note:** to be merged after #6, I'll rebase against the new master once its merged.