`format` not validating correctly

[pezholio]

If my schema has, for example:

...
{
  "name": "Date",
  "type": "date",
  "description": "",
  "constraints": {
    "format": "yyyy-mm-dd"
    "required": true
  }
}
...

And I validate against a CSV that has an incorrect date pattern e.g. "23/09/1980", then I don't get any errors.

Also, http://dataprotocols.org/json-table-schema/#field-types says that every field that has type date should match ISO8601, unless format is specified.