[Improvement] optimize staticClass (#337)

* fix: Tabbar icon line-height

* [new feature] progress add showPivot prop

* [new feature] TabItem support vue-router

* [new feature] update document header style

* [Doc] add toast english ducoment

* [bugfix] Search box-sizing wrong

* [Doc] update vant-demo respo

* [Doc] translate theme & demo pages

* [Doc] add Internationalization document

* [bugfix] remove unnecessary props

* [fix] optimize clickoutside

* [new feature] optimize find-parent

* [new feature]: change document title accordinng to language

* [new feature] Pagination code review

* [improvement] adjust icon-font unicode

* [improvement] Icon spinner color inherit

* [improvement] icon default width

* [bugfix] DateTimePicker validate date props

* [bugfix] Tab item text ellipsis

* [improvement] optimize single line ellipsis

* [Improvement] optimzie staticClass

packages/sku/components/SkuRowItem.vue

@@ -1,7 +1,8 @@
 <template>
   <span v-if="isChoosable"
     @click="onSkuSelected"
-    :class="{ 'van-sku-row__item': true, 'van-sku-row__item--active': isChoosed }">
+    class="van-sku-row__item"
+    :class="{ 'van-sku-row__item--active': isChoosed }">
     {{ skuValue.name }}
   </span>
   <span v-else class="van-sku-row__item van-sku-row__item--disabled">{{ skuValue.name }}</span>