mixin for column-width deprecated in SASS 2.0

[// Column width with margin
@mixin column-width($numberColumns: 3) {
	width: map-get($columns, $numberColumns) - ( ( $columns__margin * ( $numberColumns - 1 ) ) / $numberColumns );
}](https://github.com/Automattic/_s/blob/1c59bd66ea61d6e8e7ca796e76153c1e12779001/sass/abstracts/mixins/_mixins.scss#L9)

This mixin is deprecated and will be removed in SASS 2.0. 