[new feature] Tab support vue-router (#305)

* fix: Tabbar icon line-height

* [new feature] progress add showPivot prop

* [new feature] TabItem support vue-router

packages/mixins/router-link.js

@@ -0,0 +1,22 @@
+/**
+ * add Vue-Router support
+ */
+
+export default {
+  props: {
+    url: String,
+    replace: Boolean,
+    to: [String, Object]
+  },
+
+  methods: {
+    routerLink() {
+      const { to, url, $router, replace } = this;
+      if (to && $router) {
+        $router[replace ? 'replace' : 'push'](to);
+      } else if (url) {
+        replace ? location.replace(url) : location.href = url;
+      }
+    }
+  }
+};