features: validate iso8601 date and datetime

[zaggino]

please consider providing methods for validating the following:

isoDate: 2015-03-11
isoDateTime: 2015-03-11T13:23:51+00:00 || 2015-03-11T13:23:51Z

ref: http://en.wikipedia.org/wiki/ISO_8601

I currently use this: https://github.com/zaggino/z-schema/blob/master/src/FormatValidators.js#L6-L45 and I'd like to delegate this to your validator if possible since it's referenced for validating emails anyway

[ItalyPaleAle]

Please see http://stackoverflow.com/a/14322189/192024 for a more appropriate regular expression

[chriso]

Thanks for the request. PRs are welcome :)

[gkaimakas]

That can be done easily using moment.js which supports ISO 8601 but I am not sure if moment.js should be included as a dependency...