/// Return whether the first version is lesser than the second
/// @param {String} $v1
/// @param {String} $v2
/// @return {Boolean}
/// @example scss
///   $lt: lt('1.2.3', '3.2.1');
///   -> true
///   $lt: lt('1.2.3', '1.2.3');
///   -> false
///   $lt: lt('1.2.3', '0.1.2');
///   -> false
@function lt($v1, $v2) {
  @return neq($v1, $v2) and not gt($v1, $v2);
}