Date._<format>(nil) should return an empty Hash

[casperisfine]

Fix: #39

This is how versions previous to 3.2.1 behaved and Active Support
currently rely on this behavior.

https://github.com/rails/rails/blob/90357af08048ef5076730505f6e7b14a81f33d0c/activesupport/lib/active_support/values/time_zone.rb#L383-L384

Any Rails application upgrading to date 3.2.1 might run into unexpected errors.

[mame]

Thanks, I will merge this soon. I will make a new release in a few days

[wwahammy]

@casperisfine thanks for the PR! Does this also address the problem in 2.0.1 or just the 3.2.1 version?

[casperisfine]

@wwahammy just 3.2.1, but I assume the change was the same on the other version and it only need to be cherry-picked on these old branches.

[casperisfine]

I pushed a second commit to also handle Date._<format>(<symbol>).

In could have been a different PR, but since the fix is in the same place, the merge would have bene messy.