Enforce tests on CKAN identifiers.

CKAN identifiers have a strict definition of letters, numbers, and
dashes; and must start with a letter. This adds a test to ensure that
incorrect identifiers cannot be submitted.

With our current master, this always causes a failiure, as we have
invalid data in our repo.
Merge pull request #121 from pjf/extra_tests

Enforce tests on CKAN identifiers.