[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/coupon-list/Item.vue

@@ -1,5 +1,5 @@
 <template>
-  <div :class="['van-coupon-item', { 'van-coupon-item--disabled': disabled }]">
+  <div class="van-coupon-item" :class="{ 'van-coupon-item--disabled': disabled }">
     <div class="van-coupon-item__head">
       <div class="van-coupon-item__lines"></div>
       <div class="van-coupon-item__gradient">

packages/coupon-list/index.vue

@@ -4,7 +4,7 @@
       <van-field class="van-coupon-list__filed van-hairline--surround" v-model="exchangeCode" :placeholder="inputPlaceholder" :maxlength="20" />
       <van-button size="small" type="danger" class="van-coupon-list__exchange" :disabled="exchangeButtonDisabled || !exchangeCode.length" @click="onClickExchangeButton">{{ exchangeButtonText }}</van-button>
     </van-cell-group>
-    <div :class="['van-coupon-list__list', { 'van-coupon-list--with-exchange': showExchangeBar }]" ref="list">
+    <div class="van-coupon-list__list" :class="{ 'van-coupon-list--with-exchange': showExchangeBar }" ref="list">
       <van-coupon-item
         ref="card"
         v-for="(item, index) in coupons"