Fixed 'using / for division' deprecation warning in Sass

src/scss/helpers/_mq.scss

@@ -57,7 +57,7 @@
 /// @return {Number} - Unitless number
 @function strip-unit($number) {
     @if meta.type-of($number) == 'number' and not math.is-unitless($number) {
-        @return $number / ($number * 0 + 1);
+        @return math.div($number, ($number * 0 + 1));
     }
 
     @return $number;