Create new, pure js validator that is faster

On example data I downloaded, Joi runs in 2484 milliseconds.  Joy runs in 38 milliseconds and I believe it is verifying the same stuff.

@jebeck @nicolashery Give this a once over and make sure you believe it's verifying the same stuff as well.

I veered off from the Joi API in a couple places.  The biggest is that I assumed that things are generally required and if they are optional, that should be pointed out.  Joi does it the other way and forces you to specify what is required.
Hrm, I don't necessarily see a reason to restrict it to only Zulu time.  I mean, a fully-qualified ISO8601 string is resolvable to any UTC time, so I'm not sure it really makes that much sense to limit tideline's interface to only timestamps that end with "Z".  Fwiw, moment-timezone appears to generate timestamps with "+00:00" instead of a "Z", so adding the restriction might actually end up making it a bit more difficult for people who are using that library to adjust their data.