Carbon::setTestNow ignored during validation

[CSigelmann]

• Laravel Version: 5.4.25
• PHP Version: 5.6.30

Description:

There are a few places where strtotime() is used in Laravel, for example in getDateTimestamp in ValidatesAttributes.php. This makes it so that Carbon::setTestNow() is ignored for validation.

I feel like this should be changed in a similar manner to #15544

Steps To Reproduce:

Carbon::setTestNow(Carbon::parse('2000-01-01', 'UTC'));
$validator = Validator::make(['date' => '2005-06-06 12:00:00Z'], ['date' => 'after:now']);
dd($validator->errors()->all()); // "The date must be a date after now."

[themsaid]

Feel free to open a PR :)

Closing since it's not a bug report but rather a change request, we're open to PRs on this.