🐛 less slides than slidesToShow breaks layout(#63, #64)

* Fix #63

* ⏪ keep original style behavior

Co-authored-by: jpucheavoristravel <46667382+jpucheavoristravel@users.noreply.github.com>
Co-authored-by: KyuWoo Choi <kyuwoo.choi@gmail.com>

src/SliderTrack.vue

@@ -144,7 +144,11 @@ export default {
         )
 
         // if slide needs to be precloned or postcloned
-        if (spec.infinite && spec.fade === false) {
+        if (
+          spec.infinite &&
+          spec.fade === false &&
+          childrenCount > spec.slidesToShow
+        ) {
           let preCloneNo = childrenCount - index
           if (
             preCloneNo <= getPreClones(spec) &&