[bugfix] remove unnecessary props (#323)

* 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

packages/tag/index.vue

@@ -1,19 +1,14 @@
 <template>
-  <span :class="['van-tag', 'van-hairline--surround', { [`van-tag--${type}`]: type, 'is-plain': plain, 'is-mark': mark }]">
+  <span :class="['van-tag', 'van-hairline--surround', { [`van-tag--${type}`]: type, 'van-tag--plain': plain, 'van-tag--mark': mark }]">
     <slot></slot>
   </span>
 </template>
 
 <script>
-const ALLOW_TYPE = ['danger', 'success', 'primary'];
-
 export default {
   name: 'van-tag',
   props: {
-    type: {
-      type: String,
-      validator: val => ~ALLOW_TYPE.indexOf(val)
-    },
+    type: String,
     mark: Boolean,
     plain: Boolean
   }