Error messaging triggers too early on reader-facing form

[kgardnr]

Errors and alerts should not trigger until a reader is done filling out the question [eg date, numbers]

Date validation error message appears too early -- before someone has even tried to enter a year

[okbel]

https://github.com/coralproject/elkhorn/pull/100

[riley]

@okbel if I enter a date in only the first box, the form still lets me submit without errors. Is this expected?

https://s3.amazonaws.com/nyt-stage/57d99cf90cefe52294d0ff63.html