[new feature] Uploader: support bind v-model

packages/uploader/test/__snapshots__/demo.spec.js.snap

@@ -18,6 +18,14 @@ exports[`renders demo correctly 1`] = `
       </div>
     </div>
   </div>
+  <div>
+    <div class="van-uploader">
+      <div class="van-uploader__wrapper">
+        <div class="van-uploader__upload"><i class="van-icon van-icon-plus van-uploader__upload-icon">
+            <!----></i><input multiple="multiple" type="file" accept="image/*" class="van-uploader__input"></div>
+      </div>
+    </div>
+  </div>
   <div>
     <div class="van-uploader">
       <div class="van-uploader__wrapper">

packages/uploader/test/index.spec.js

@@ -127,7 +127,12 @@ it('render upload-text', () => {
 it('render preview image', async () => {
   const wrapper = mount(Uploader, {
     propsData: {
-      preview: true
+      fileList: []
+    },
+    listeners: {
+      input(fileList) {
+        wrapper.setProps({ fileList });
+      }
     }
   });
 
@@ -140,8 +145,13 @@ it('render preview image', async () => {
 it('max-count prop', async () => {
   const wrapper = mount(Uploader, {
     propsData: {
-      preview: true,
+      fileList: [],
       maxCount: 1
+    },
+    listeners: {
+      input(fileList) {
+        wrapper.setProps({ fileList });
+      }
     }
   });
 
@@ -154,8 +164,13 @@ it('max-count prop', async () => {
 it('preview-size prop', async () => {
   const wrapper = mount(Uploader, {
     propsData: {
-      preview: true,
+      fileList: [],
       previewSize: 30
+    },
+    listeners: {
+      input(fileList) {
+        wrapper.setProps({ fileList });
+      }
     }
   });