test(NavBar): update test cases

src/badge/test/__snapshots__/index.spec.js.snap

@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`should render content slot and match snapshot 1`] = `<div class="van-badge">Custom Content</div>`;
+exports[`should render content slot correctly 1`] = `<div class="van-badge">Custom Content</div>`;
 
 exports[`should render nothing when badge is empty string 1`] = `<!---->`;
 

src/badge/test/index.spec.js

@@ -31,7 +31,7 @@ test('should render nothing when badge is zero', () => {
   expect(wrapper.html()).toMatchSnapshot();
 });
 
-test('should render content slot and match snapshot', () => {
+test('should render content slot correctly', () => {
   const wrapper = mount(Badge, {
     slots: {
       content: () => 'Custom Content',