Add the ability to do dry runs.

[devinpearson]

It would be nice to run this without actually transferring.

So be able to disable the cron and have a message displayed with the amount that would transfer and the direction of transfer.

This would lower the level of commitment needed to try it out.

[devinpearson]

I would also like to test this out with credentials that don't have the transfer scope. It should then gracefully fail.