Fix DateValidatorType

[cruisediary]

Given func testDateValidation() does not cover after target date because it's same to target date

let targetDate = "2018-05-29T12:00+09:00".date(format: .iso8601Auto)!.absoluteDate
let afterTargetDate = "2018-05-29T12:00+09:00".date(format: .iso8601Auto)!.absoluteDate

• Add unit test for after target date and fix failed test case
• Add unit test for same target date when validate with .shouldBeforeThen or .shouldAfterThen fix failed test case

related links
https://developer.apple.com/documentation/foundation/comparisonresult

Constants
case orderedAscending
The left operand is smaller than the right operand.

case orderedSame
The two operands are equal.

case orderedDescending
The left operand is greater than the right operand.

[vbmania]

Thank you for your HELP! ^^
I will review and approve pull-request as soon as possible.

역시 크루 짱!

[vbmania]

날짜 계산하면서 겁나 헷갈렸는데 감사합니다 ^^