Removed the use for strip-unit in shake function

src/effects/_shake.scss

@@ -1,12 +1,12 @@
 /// Creates a shaking animation.
-/// @param {Number} $intensity [7%] - Intensity of the shake, as a percentage value.
+/// @param {Percentage} $intensity [7%] - Intensity of the shake, as a percentage value.
 /// @return {Map} A keyframes map that can be used with the `generate-keyframes()` mixin.
 @function shake($intensity: 7%) {
   $right: (0, 10, 20, 30, 40, 50, 60, 70, 80, 90);
   $left: (5, 15, 25, 35, 45, 55, 65, 75, 85, 95);
 
   $keyframes: (
-    name: 'shake-#{strip-unit($intensity)}',
+    name: 'shake-#{($intensity / 1%)}',
     $right: (transform: translateX($intensity)),
     $left: (transform: translateX(-$intensity)),
   );