增加goodsDiscount按钮效果

@@ -75,8 +75,14 @@ $('#nav-tab li').on('click', function() {
 
 $('.goodsDiscount .dropdown').on('click', function() {
     if ($('.goodsDiscount .discount-folder').is(':hidden')) {
+        $('.goodsDiscount .first-item span').removeClass('icon-down');
+        $('.goodsDiscount .first-item span').addClass('icon-up');
+        $('.goodsDiscount .first-item span').html('');
         $('.goodsDiscount .discount-folder').slideDown();
     } else {
+        $('.goodsDiscount .first-item span').removeClass('icon-up');
+        $('.goodsDiscount .first-item span').addClass('icon-down');
+        $('.goodsDiscount .first-item span').html('');
         $('.goodsDiscount .discount-folder').slideUp();
     }
 });

@@ -45,7 +45,7 @@
 <div class="goodsDiscount">
     {{#each list}}
         {{#if @first}}
-            <h1>{{this}}<span class="iconfont dropdown">&#xe609;</span></h1>
+            <h1 class="first-item">{{this}}<span class="icon-down iconfont dropdown">&#xe609;</span></h1>
             <div class="discount-folder">
             {{else}}
             <h1 class="folder-item">{{this}}</h1>