Add Coverage validator to zip importer

[val99erie]

Background Info
When I was deleting the code for the CSV importer (now replaced by the ZIP importer), I found a CoverageValidator, but I couldn't immediately figure out how to make it work with the ZIP importer.

Here's the old code for the:

• CoverageValidator
• CoverageValidator spec

I suggest that you start with a zip file that is known to import correctly, such as spec/fixtures/import_zips_in_dir/gford-20140000-010011_belfor1r.zip and edit the ISO XML file to remove some of the 4 coverage fields. (There are fields for north, south, east, west limits, and they are all required fields.) A zip with that invalid ISO file should fail to import.

Note:

I removed the code for the CoverageValidator and there were specs for it, but I'm not sure if it was actually hooked up to the CSV importer. I couldn't find any place where the validator was invoked or registered with the importer, so it's possible that this code was never working.

Acceptance Criteria

• If I have a zip file that is missing one of the 4 coverage fields in the ISO XML file, the validator should catch it and give a good error message about which field(s) are missing.