Catalog goes to pick the $ref online when in test scope

[Mitridata]

if in the schema in the unit tests are present refs like:
$ref": "http://justice.gov.uk/json/schemas/core/data-types.json#/definitions/uuid
it will try to go to pick up them online and we get an:
java.io.UncheckedIOException: java.net.UnknownHostException: justice.gov.uk

[ERROR] EmployerHandlerTest.shouldDeleteEmployer:171 » UncheckedIO java.net.UnknownHos...
[ERROR] EmployerHandlerTest.shouldUpdateEmployer:117 » UncheckedIO java.net.UnknownHos...

the same test passes if there are not external references on the schema.
JsonEnvelopeMatcher.thatMatchesSchema()