Implement the Mandrill notifier.
Implement notification of deploy job result.
Add some documentation around settings.
Use a boolean flag for indicating whether we notify on success.

If notification settings are provided, we should *always* notify on
failure. It's notifying on success that we'll want to turn on or off.
Since that's a simple boolean, it should be represented as such.
Cleanup a few things from my inadvertant rebase. Lolz.
Merge pull request #3 from hacklanta/red-flashing-light

Implement email notification.