Add rough first pass at the option to obfuscate values

[brendanlensink]

For #6

Adds:

• the --obfuscate tag, which allows you to toggle value obfuscation.
• cleans up the logging logic a little, moving the check for debug to a singleton rather than having to pass our debug setting around into our helper models.

Questions:

• Do we maybe want to flip the logic here and just obfuscate by default?
• @nbrooke I tried to google around a little to understand how Swift apps get compiled and what the executable ends up looking like, but wasn't able to get a really satisfying answer, but I'm really curious how secure this actually is?

Like we're providing the salt right in the same file, so theoretically all the information you need to decrypt the values are right there. I know security by obfuscation isn't supposed to be rock solid, but am mostly just curious how much of a different this makes.