HTML5 date inputs should not be wrapped in vertical_multi_select

[felunka]

The default initializer wrapps the date input in the vertical_multi_select: https://github.com/heartcombo/simple_form-bootstrap/blob/8d78a912847484246ef559f4f6a536ee46f1db6d/config/initializers/simple_form_bootstrap.rb#L364

This will render a arrow like a dropdown in the date input: Firefox: Chrome:

The arrow can not be clicked and a user has to actively click left of the arrow to be able to open the date picker.

Removing the line from the initializer will remove the arrow and make the whole input clickable.