[Improvement] Optimize demo test (#1053)

packages/contact-card/test/__snapshots__/demo.spec.js.snap

@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`renders contact-card correctly 1`] = `
+exports[`renders demo correctly 1`] = `
 <div>
   <div>
     <div class="van-contact-card van-contact-card--add">
@@ -47,13 +47,13 @@ exports[`renders contact-card correctly 1`] = `
     <div class="van-popup van-popup--bottom" style="display:none;">
       <div class="van-contact-edit">
         <div class="van-cell-group van-hairline--top-bottom">
-          <div maxlength="30" placeholder="名字" class="van-cell van-hairline van-field">
+          <div maxlength="30" placeholder="张三" class="van-cell van-hairline van-field">
             <!---->
             <div class="van-cell__title"><span>联系人</span>
               <!---->
             </div>
             <div class="van-cell__value">
-              <input type="text" maxlength="30" placeholder="名字" class="van-field__control">
+              <input type="text" maxlength="30" placeholder="张三" class="van-field__control">
               <!---->
               <!---->
               <!---->

packages/contact-card/test/demo.spec.js

@@ -0,0 +1,4 @@
+import Demo from '../demo';
+import demoTest from '../../../test/demo-test';
+
+demoTest(Demo);

packages/contact-card/test/index.spec.js

@@ -1,4 +0,0 @@
-import ContactCard from '../';
-import demoTest from '../../../test/demo-test';
-
-demoTest(ContactCard);