Person Not Found Exceptions

[caseywatts]

Try testing with a bogus email address, etc - it will crash the app. We should:

1. Catch any/all lookup exceptions elegantly
2. Determine the exception we should raise when the problem is we can't find someone, raise that one and catch it specifically (is there a standard / ruby core version of "NobodyFound" we should use?)

Related to this YaleLDAP issue, except we need the same functionality for magstripe and prox card - I'm not sure where it should live.
YaleSTC/yaleldap#4

[caseywatts]

I want to wait to do this until we get the API version of card lookup (instead of the database one). I want to catch all of the errors in a consistent way.

[caseywatts]

going to use self.errors.add_to_base("Person Not Found")

[caseywatts]

Not add_to_base, that's just for ActiveRecord. After talking with Oren and Simon we decided to rescue and re-raise the error with a better message.

Done, and merged into master!