[improvement] props default value (#2183)

packages/sku/Sku.vue

@@ -160,11 +160,13 @@ export default create({
   props: {
     sku: Object,
     goods: Object,
+    quota: Number,
     value: Boolean,
     buyText: String,
+    quotaUsed: Number,
     goodsId: [Number, String],
-    stepperTitle: String,
     hideStock: Boolean,
+    stepperTitle: String,
     getContainer: Function,
     resetStepperOnHide: Boolean,
     resetSelectedSkuOnHide: Boolean,
@@ -174,14 +176,6 @@ export default create({
       type: Object,
       default: () => ({})
     },
-    quota: {
-      type: Number,
-      default: 0
-    },
-    quotaUsed: {
-      type: Number,
-      default: 0
-    },
     showAddCartBtn: {
       type: Boolean,
       default: true