Add color modifier for the unchecked state

[madmatah]

Hi,

Thanks for your bulma-extensions !

I added more color modifiers to the switch, to be able to define the color when the checkbox is unchecked.

• is-unchecked-info
• is-unchecked-warning
• is-unchecked-danger
• ...etc

Example :

<div class="field">
  <input id="switchColorSuccess" type="checkbox" name="switchColorSuccess" class="switch is-success is-unchecked-danger" checked="checked">
  <label for="switchColorSuccess">Switch success</label>
</div>

It was useful for me in a project because i had a lot of use cases and the $switch-background variable was not enough for my needs.
I open a pull request because it may help other people :-)

[Wikiki]

Thanks a lot 😉