[CS] Error on missing zip codes in two spots
[CS] Error on missing zip codes in two spots

Polling locations and early vote sites were missing a validation on
missing zip codes. They have been added at the error level, since their
presence isn't strictly required for display. (However, their absence
will end up with invalid XML, as they are required by the spec... at
least people will know why the XML is invalid.)

votinginfoproject/data-processor