Add Logging

This PR addresses #7 by pulling in the logging from `Sprig` and sending logging messages when appropriate.  Where I could predict failure, I added rescue statements with `log_error` calls so the `reap` won't be halted by a single error.  Rather, errors will be logged and the `reap` will try to continue on.  I also added logging messages when starting a `reap`, on every completed file write (once per model), and when the `reap` completes.