Ok, working around case class limits has just gotten annoying.
Add StripeHelpers class for dealing with JSON name translation.
Update Customer to be a regular case class.

Since we don't have a case class limit, we don't have to worry about
this anymore.
New definition of what it means to be a StripeObject.

This is moving the right direction.
Implement Charge as a case class.
Get The Other Stuff™ compiling until I get a chance to flesh it out.
Add a spec covering Charge's fields.
Now presenting the new and improved Card object.