Fix casing on method name
Fix casing on method name

To avoid errors like `PHP Strict standards:  Declaration of Cake\I18n\Time::diffForHumans() should be compatible with Cake\Chronos\MutableDateTime::diffForhumans(Cake\Chronos\ChronosInterface $other = NULL, $absolute = false)`

See the interface: https://github.com/cakephp/chronos/blob/master/src/ChronosInterface.php#L868
cakephp/chronos,antograssiot/chronos