fix(slide): update currentIndex in scrollEnd handler

#278

src/components/slide/slide.vue

@@ -206,9 +206,10 @@
 
         this.slide = new BScroll(this.$refs.slide, options)
 
+        this.slide.on('scrollEnd', this._onScrollEnd)
+
         this.slide.goToPage(this.currentPageIndex, 0, 0)
 
-        this.slide.on('scrollEnd', this._onScrollEnd)
         /* dispatch scroll position constantly */
         if (this.options.listenScroll && this.options.probeType === 3) {
           this.slide.on('scroll', this._onScroll)